<PAGE>

                                                                   EXHIBIT 10.12


                           STOCK PURCHASE AGREEMENT



                                    Between


Mr. Andreas Zwimpfer, Riedsortstrasse 59, 6553 Weggis, Switzerland

Mr. David Keat, Doffstrasse 227, 5462 Siglistorf, Switzerland

Mr. Charles Fraefel, Maienweg 8, 5102 Rupperswil, Switzerland

Mr. Chula de Silva, Dorfstrasse 59, 5425 Schneisingen, Switzerland

Mr. Tim Moser, Bergackerstrasse 33, 6330 Cham, Switzerland

                                                                   "the Sellers"


                                      and


Viador, Inc., 167 Second Ave., San Mateo, CA, USA 94401

                                                                 "the Purchaser"

WHEREAS Viador AG, Tafernstrasse 4, 5405 Baden-Dattwil, Switzerland (the
"Company"), has a share capital of CHF 100'000, divided into 100 registered
shares with a nominal value of CHF 1'000 each;

WHEREAS the Sellers together own all registered shares of the Company;

WHEREAS the Sellers intend to sell these shares to the Purchaser and the
Purchaser intends to purchase such shares from the Sellers;
<PAGE>

NOW, THEREFORE the parties have come to the following agreement.


                                   ARTICLE 1
                                   ---------
                         Sale and Purchase of Shares,
                         ----------------------------
                                Purchase Price
                                --------------

1.1  Sale and Purchase of Shares. Subject to the terms and conditions defined
     ---------------------------
     herein, Sellers hereby agree to sell and transfer to Purchaser and
     Purchaser agrees to buy from the Sellers, all of their respective rights,
     title and interest in and to 100 registered shares of the Company with a
     nominal value of CHF 1'000 each.

1.2  Purchase Price. The purchase price amounts to USD 20'000 per share, i.e.
     --------------
     USD 2'000'000 (United States Dollars two million) for all the shares sold
     pursuant to art. 1.1 of this Agreement.

     The purchase price shall be paid as follows:

(a)  On the Closing Date, Purchaser shall pay to each of the Sellers a total sum
     of USD 1'000'000 (United States Dollars one million) allocated between and
     amongst the respective Sellers as set forth in Exhibit 1.2.a.
                                                            -----

(b)  At any time after the Closing Date that Purchaser, at its sole discretion
     may so elect, but no later than three Business Days (as defined in art. 1.5
     of this Agreement) following the first anniversary of the Closing Date (the
     "Payment Date"), the Purchaser shall deliver to each Seller either of the
     following: (i) such number of registered shares in the Purchaser that,
     based on the twenty
<PAGE>

     days average NASDAQ closing price of Purchaser's stock for the twenty days
     period ending three Business Days prior to the Payment Date, corresponds to
     the amount in United States Dollars as set forth in Exhibit 1.2.b next to
                                                         -------------
     such Seller's name (the "Future Shares"), it being understood that any
     fractions of Future Shares below one shall be paid out in cash to the
     respective Seller or, (ii) the actual net amount of United States Dollars
     as set forth in Exhibit 1.2.b. Purchaser's election to make said payment by
                     -------------
     delivery of Future Shares or by cash as set forth herein, shall be within
     Purchaser's sole discretion. Should Purchaser by the Payment Date neither
     have delivered the Future Shares nor paid the amount provided for under
     this article 1.3 (b), then Purchaser shall exclusively be entitled and
     shall exclusively be obliged to effect the cash payment as provided for
     under this article 1.3 (b). In such an event the Purchaser shall, in
     addition, pay an interest rate of twelve (12) percent per year on the
     amount due (including interest accrued thereon pursuant to article 1.3),
     such interest being due as from the Payment Date.

     If the Purchaser is no longer listed on NASDAQ or some equivalent stock ex-
     change and/or if a third party gains control over the Purchaser, the
     Purchaser shall no longer hand over the Future Shares to the Sellers as
     provided for by this art. 1.2 (b) but shall, within 10 days after such
     event pay to the Sellers the amount that is set forth in Exhibit 1.2b. A
                                                              ------------
     third party gains control over the Purchaser in the sense of this article
     1.2 (b) if it, alone or in a concerted action with others, directly or
     indirectly, acquires at least fifty percent of all the shares in the
     Purchaser or appoints at least half of the Purchaser's board members.

1.3  Interest on Amounts Owing. Purchaser shall pay six percent (6%) interest
     per annum on all amounts owing to Sellers. Payment of such interest shall
     be by the same means, and subject to the same terms, conditions and
     limitations,
<PAGE>

     set forth in art. 1.2, 1.2(a) and 1.2(b) herein. Interest shall be payable
     from the first day following the Closing Date and shall be calculated based
     on a 365 days calendar year. There shall be no prepayment penalty.

1.4  Notice of Payment Date. Purchaser shall give notice of the Payment Date to
     Sellers no later than twenty Business Days preceding the Payment Date.

1.5  Business Days. For purposes of this Agreement a Business Day shall mean any
     other day than a Saturday, a Sunday or a day on which commercial banks in
     the State of California are required or authorized to be closed by the law
     of the State of California or by U.S. Federal Law.

                                   ARTICLE 2
                                   ---------
                                    Closing
                                    -------

2.1  Closing Date of Transaction. The transaction described in this Agreement
     ---------------------------
     shall be consummated at the offices of Baker & McKenzie, at Zollikerstrasse
     225 in Zurich, on January 20, 2000. The date at which the transaction
     described in this Agreement is to be consummated shall hereinafter be
     referred to as the "Closing Date".

2.2  Transfer of Shares and Payment of Purchase Price.
     ------------------------------------------------

a)   On the Closing Date, Sellers shall deliver to Purchaser:

     -  100 registered shares of the Company with a nominal value of CHF 1'000
        each, endorsed in blank;

     -  an unanimous written resolution of the Company's Board of Directors
<PAGE>

        consenting to the transfer of these shares to the Purchaser and the re-
        gistration of the Purchaser as sole shareholder in the Company's share
        register;

     -  the share register of the Company in which the Purchaser has been
        registered as shareholder for the amount of shares purchased;

     -  letters of resignation of the Company's directors in accordance with
        art. 5 of this Agreement.

b)   On the Closing Date, Purchaser shall pay a net amount of USD 1'000'000
     (United States Dollars one million) to be used as payment to Sellers in
     frac-tions indicated next to each Seller's name in Exhibit 1.2a. On the
                                                        ------------
     Closing Date, Purchaser, directly or indirectly as it may decide in its
     sole discretion, shall transfer USD 1'000'000 to a trust account of
     Sellers' Swiss Counsel Baker & McKenzie at UBS AG in Zurich-Bellevue,
     account No. 225-P2718045.5 for further distribution to the Sellers in
     accordance with Exhibit 1.2a. For purposes of this Article 2.2 the payment
     by Purchaser shall be effected and completed upon arrival of USD 1'000'000
     net in the UBS trust account. Purchaser shall then have met all of its
     obligations under this art. 2.2b and shall have no responsibility for the
     further transfer of the respective amounts each of the Sellers.

c)   If Purchaser elects to transfer its registered shares, in lieu of cash, as
     set forth in Art. 1.2(b), no later than three Business Days following the
     first anniversary of the Closing Date, the Purchaser shall

     - deliver to each of the Sellers a copy of an unanimous written resolution
       of the Purchaser's board of directors consenting to the transfer of these
<PAGE>

        shares to the Sellers and the registration of the Sellers as
        Shareholders in the Purchaser's share register;

     -  deliver to each of the Sellers a copy of the respective entries in the
        share register of the Purchaser in which the Sellers have been
        registered as Shareholders for the amount of shares they receive
        pursuant to art. 1.2 (b).

     -  deposit with a bank or broker, to be designated by each of the Sellers
        in accordance with art. 2.3 of this Agreement, such number of Future
        Shares as this Seller is entitled to pursuant to art. 1.2 (b). Such
        delivery may, within the sole discretion of the Purchaser, be effected
        through physical delivery of share certificates or in book entry form.

     -  deliver to each of the Sellers the opinion of Purchaser's counsel as
        provided for under art. 4.5.

2.3  Designation of Accounts. In order to enable the Purchaser to effect, at its
     sole discretion, the cash payment (which shall be effected through wire
     transfer) or the delivery of Future Shares as provided for in art. 1.2(b)
     hereof, each of the Sellers shall, no later than 20 Business Days following
     the Closing Date, notify in writing to the Purchaser, (i) his bank account
     to which any cash payment shall be made and (ii) his bank deposit and/or
     brokerage account to which any delivery of Future Shares shall occur.
     Each Seller may at any time, but no later than ten Business Days prior to
     the first anniversary of the Closing Date and, in any event, no later than
     ten Business Days after the Purchaser's notice of election in accordance
     with article 1.2 (b), notify the Purchaser in writing of another bank
     account and/or bank deposit and/or brokerage account.
<PAGE>

2.4  Right to Rescind the Agreement. Sellers may rescind this Agreement if the
     ------------------------------
     amounts provided for in Exhibit 1.2b are not paid on the Closing Date as
     provided for in art. 2.2b of this Agreement.

     Purchaser may rescind this Agreement if the documents mentioned in art.
     2.2.a of this Agreement are not remitted on the Closing Date.

                                   ARTICLE 3
                                   ---------
                   Representations and Warranties of Sellers
                   -----------------------------------------

Sellers jointly and severally represent and warrant for the Company as follows
(articles 3.1 through 3.18):

3.1  Organization and Qualification. The Company is duly organized and validly
     ------------------------------
     exists under the laws of Switzerland and has full right and authority to
     own and to operate its properties and to engage in the business in which it
     is now engaged. Exhibit 3.1 contains the Articles of Incorporation and
                     -----------
     organizational regulations of the Company as in force on the Closing Date.

3.2  Capital Structure. As of the Closing Date, the Company has a share capital
     -----------------
     of CHF 100'000. No further capital, non-voting stock, convertible
     securities or similar rights in the Company have been or will by the
     Closing Date be created, issued, or agreed to be issued. All the shares
     sold pursuant to art. 1.1 of this Agreement have been validly issued and
     fully paid-in, and represent all ownership interest in the Company.

3.3  Ownership. As of the Closing Date, Sellers are the sole owners of and have
     ---------
<PAGE>

     good and valid title to the shares sold in accordance with art. 1 of this
     Agreement, free and clear of all liens, encumbrances, options, charges,
     equities and claims arising from any privilege, pledge or security
     arrangement. On the Closing Date Sellers have full right and capacity to
     transfer and sell complete title to such shares.

     Upon delivery of the documents mentioned in art. 2.2.a of this Agreement,
     Purchaser will receive good and valid title to such shares, free and clear
     of all liens, encumbrances or other rights of third parties.

3.4  Minutes of the Shareholders' Meetings and of the Board of Directors'
     --------------------------------------------------------------------
     Meetings. Exhibit 3.4 contains true copies of all the Minutes of
     --------  -----------
     Shareholders' Meetings and Directors Meetings of the Company. The Sellers
     warrant that neither the shareholders' meeting nor the board of directors
     of the Company have adopted any resolutions which are not recorded in these
     minutes.

3.5  Financial Statements. Exhibit 3.5 contains the balance sheets and the
     --------------------  -----------
     profit and loss statement of the Company as of December 31, 1999. These
     financial statements are in accordance with U.S. Generally Accepted
     Accounting Principles and show a true and fair view of the financial
     condition of the Company as of December 31, 1999.

     In particular, on December 31, 1999 the Company had no more liabilities
     (including contingent liabilities) than those recorded on the balance
     sheets set forth, in Exhibit 3.5.
                          -----------

     In particular, the Company has good and clear title, free of all liens
     and/or other encumbrances whatsoever, to all assets listed on the balance
     sheets set forth in Exhibit 3.5.
                         -----------
<PAGE>

3.6  Absence of Adverse Changes. Sellers represent and warrant that in the
     --------------------------
     period between December 31, 1999 and the Closing Date, the Company:

     -  has not suffered any adverse changes in their financial position or
        assets or business;

     -  has conducted its business in the ordinary course and has not made any
        unusual contracts, contract changes or commitments, and has not sold,
        assigned or transferred any tangible or intangible assets other than in
        the ordinary course of business;

     -  has not incurred any obligation or liability (absolute or contingent)
        except current liabilities incurred in the ordinary course of business
        and has not mortgaged, pledged or subjected to a lien or encumbrance any
        of its tangible or intangible assets;

     -  has not suffered any damage, destruction or loss by fire or other
        casualty;

     -  has not made any declaration, setting aside, or payment of any dividend
        or any other distribution of profit, or any direct or indirect
        redemption, purchase or other acquisition of any quotas or shares of the
        Company;

     -  has not increased the total compensation payable to its employees, and
        has not adopted any profit sharing plan, bonus plan or new pension or
        benefit plan.

3.7  Permits and Authorizations. The Company has all the permits and authori-
     --------------------------
<PAGE>

     zations which are necessary to carry on its business. The fact that this
     Agreement is executed and the transaction contemplated herein is
     consummated will not lead to the automatic termination of such permits and
     authorizations and will also not give rise to any right of the competent
     authorities or other third parties to terminate such permits and
     authorizations.

3.8  Claims and Litigation. As of the Closing Date, there are no actions, suits
     ---------------------
     or proceedings pending or threatened or likely to be asserted against the
     Company either in court or before any administrative board, agency or
     commission.

3.9  Taxes. As of the Closing Date, the Company has timely filed all tax returns
     -----
     for income taxes, sales taxes, withholding taxes, stamp taxes, payroll
     taxes, social security taxes and property taxes and all other taxes of
     every kind whatsoever required by law to have been filed, and all such tax
     returns are complete and accurate. Sellers are liable for any taxes to be
     paid on constructive dividends paid by the Company to the Sellers or to
     third parties before the Closing Date.

     The Company has paid or made adequate provisions for all taxes which have
     become due by the Closing Date, whether pursuant to said returns or
     pursuant to any assessment, and there is no further liability for any such
     taxes and no interests or penalties accrued or accruing with respect
     thereto.

3.10 Agreements with Third Parties. The Company is not in default under any
     -----------------------------
     agreements to which it is a party. Sellers, furthermore, represent and
     warrant that neither the execution of this Agreement nor the consummation
     of the transaction contemplated herein will terminate any agreements to
     which the Company is a party or give rise to any right of a third party to
     terminate such
<PAGE>

     agreements. This Agreement, when effective, shall not cause any breach (ma-
     terial or minor) of any agreement to which the Sellers or the Company or
     any of them is a party.

     Exhibit 3.10 contains copies of all the following agreements which the
     ------------
     Company has concluded:

     -  license agreements;

     -  leases and leasing contracts which provide for annual payments of more
        than CHF 10'000;

     -  agreements with suppliers or customers with a term of more than three
        months or a contract value of more than CHF 10'000 or which grant
        customers a payment term of more than sixty days;

     -  contracts with works councils, labor unions and/or other employee
        organizations;

     -  distributorship and agency agreements;

     -  guarantees and sureties granted with respect to any obligation of third
        parties (including the Sellers and any parties related with him);

     -  joint venture and cooperation agreements;

     -  confidentiality agreements;

     -  management and consulting agreements;
<PAGE>

     -  severance contracts with employees, agents and distributors,

     -  non-compete agreements and non-solicitation agreements obliging the
        Company;

     -  other contracts or commitments in excess of CHF 10'000 or which cannot
        be terminated on three months notice without payment of compensation.

     -  other agreements, which contain any provision limiting or prohibiting
        any rights of assignment or sublicense, including but not limited to
        such limitations or prohibitions resulting from a change of ownership
        clause contained in such agreements.

     -  other shareholder agreements (including without limitation voting
        agreements, voting pooling agreements, proxy agreements, share transfer
        agreements, warrant and/or option agreements, co-sale agreements, buy-
        sell agreements and share purchase agreements).

     -  other agreements which contain an indemnity provision and/or hold
        harmless provision in which the Company is an indemnitor or may
        otherwise be obliged to hold any other party harmless from any amount of
        loss, damage, liability or the like.

     Sellers warrant that these copies are true, accurate and complete, these
     agreements are binding and in force on the Closing Date, the text of these
     agreements covers the full scope of such agreements and that there are no
     other oral or written agreements between the Company and the third parties
     concerned.
<PAGE>

3.11 Intellectual Property/Know-how. The Company owns at the Closing Date all
     ------------------------------
     the know-how and all patents, trademarks, trade names, copyrights, domain
     names and other intellectual property rights which are necessary for the
     conduct of its business as it is now conducted. In particular, all the
     patents, trade names, copyrights, trademarks and domain names set forth in

     Exhibit 3.11 are valid and owned by the Company. Furthermore, Sellers
     ------------
     warrant that such patents, trade names, copyrights, trademarks and domain
     names do not violate the rights of any third party, third parties do not
     have any rights to and, to the best of Sellers' knowledge, are not
     infringing such patents, trade names, copyrights, trademarks and domain
     names and that the Company has no obligations to disclose such patents,
     trade names, copyrights, trademarks and domain names to any third
     parties.

3.12 Employment Matters. Exhibit 3.12 contains true copies of all employment
     ------------------  ------------
     agreements of the Company concerning employees which have either signature
     authority or a yearly salary exceeding CHF 12'000. Sellers warrant that the
     text of these agreements covers the full scope of the agreements between
     the Company and the employees concerned and that there are no other
     agreements concerning the employment relationship. Sellers, furthermore,
     warrant that such agreements are binding and in force on the Closing Date.

3.13 Social Security. Sellers warrant that all filings necessary in connection
     with social security matters (AHV/IV/EO/ALV) have been made and that all
     payments due have been timely effected.

3.14 Pension Plan. Sellers warrant that all accrued pension claims of the Com-
     pany's present and former employees are adequately covered by funds of spe-
     cial foundations by insurance contracts or by provisions the Company has
<PAGE>

     specifically established for such purpose and that all insurance premiums,
     if any, have been paid or accrued.

3.15 Insurance Policies. With the exception of insurance policies covering
     ------------------
     single cars, all insurance policies of the Company are contained in Exhibit
     3.13. Sellers warrant that such policies are in full force at the Closing
     Date and that the Company has done nothing either by way of action or
     inaction which might lead to the cancellation of such policies. Sellers,
     furthermore, warrant that such insurance coverage is adequate for the risks
     associated with the Company's activities and assets.

3.16 Compliance with Legal Requirements. The Company has not violated
     ----------------------------------
     applicable laws, ordinances, regulations, decrees or orders of any
     government entity.

     Sellers warrant, in particular, that the Company and its plants, real
     estate and equipment comply with all applicable labor, occupational health
     and safety and environmental laws, regulations, decrees and orders, and the
     competent authorities have not informed the Company that they will issue
     any orders with which the Company does not yet comply as of the Closing
     Date.

3.17 Product Liability. Sellers warrant that third parties have no claims
     -----------------
     against the Company in connection with any products delivered or services
     rendered by the Company before the Closing Date.

3.18 Disclosure. Purchase has conducted a preliminary due diligence review. All
     ----------
     information furnished by or on behalf of Sellers in connection with the
     trans- action contemplated by this Agreement is accurate in all material
     respects and Sellers are not aware of any facts of materially adverse
     significance to the
<PAGE>

     Company, its properties, or business operations which are not disclosed in
     this Agreement or the Annexes to this Agreement.

                                   ARTICLE 4
                                   ---------
                  Representations and Warranties of Purchaser
                  -------------------------------------------

Purchaser represents and warrants for the Purchaser the following (articles 4.1
through 4.6):

4.1  Organization and Qualification. The Purchaser is duly organized and validly
     ------------------------------
     exists under the laws of the State of Delaware and has full right and
     authority to own and to operate its properties and to engage in the
     business in which it is now engaged.

4.2  Authority. The Purchaser has the right, power and authority to execute and
     ---------
     deliver this Agreement and to carry out its obligations hereunder. The
     execution, delivery, and performance of this Agreement and the
     consummation of the transactions contemplated hereby have been duly
     authorized by the board of directors of Purchaser, and no other proceeding,
     authorization or approval on the part of the Purchaser is necessary to
     authorize the execution and delivery of this Agreement or the performance
     by the Purchaser of any of the transactions contemplated hereby. This
     Agreement has been duly executed and delivered by the Purchaser, and when
     executed and delivered by all required parties thereto, will be legal,
     valid, and binding obligations of the Purchaser enforceable against the
     Purchaser in accordance with their respective terms, subject to applicable
     bankruptcy, insolvency and other similar laws of general application
     affecting the rights of creditors.
<PAGE>

4.3. Approvals. Except as set forth in Exhibit 4.3, no consent, approval,
     ---------                         -----------
     order, or authorization of, or notice of registration, filing with, any
     governmental authority or third party is required by the Purchaser in
     connection with the execution and the delivery of this Agreement, or the
     consummation of the transactions contemplated hereby.

4.4. Non-Contravention. The execution and delivery of this Agreement and the
     ------------------
     consummation of the transactions contemplated hereby will not (a) violate
     any provision of the by-laws of the Purchaser; and, to the best of
     Purchaser's knowledge, (b) violate any material obligation under any
     contract to which the Purchaser is a party or by which it or any of its
     assets is bound; (c) violate any lien or result in the creation or
     imposition of any material lien upon any property of the Purchaser; or (d)
     violate or conflict with any other material restriction or any law,
     ordinance, rule, order, arbitration award, judgment or decree to which the
     Purchaser or any of its property is subject.

4.5  Ownership. If Purchaser elects to transfer its registered shares, in lieu
     ---------
     of cash, as set forth in art. 1.2(b), then Purchaser shall deliver to
     Sellers good and valid title to the shares in accordance with art. 2.2.c of
     this Agreement, free and clear of all liens, encumbrances, options,
     charges, activities and claims arising from any privilege, pledge or
     security arrangement and do not bear any restrictive legend. To that
     effect, Purchaser shall also be required to issue instructions and hand
     over an opinion of its counsel that the shares are saleable without
     restriction on NASDAQ under U.S. law, to Seller's transfer agent.

     On the first anniversary of the Closing the Future Shares will have been
     validly issued and fully paid in. Immediately following the transfer the
     Sellers
<PAGE>

     can, without any restriction, sell all Future Shares on NASDAQ.

4.6  Partial Liquidation. Purchaser agrees not to take any measures within a
     -------------------
     period of five years as from the Closing Date that would qualify as an
     indirect partial liquidation in the sense of Swiss tax law. In particular,
     Purchaser agrees not to merge the Company and guarantees that the Company
     does not pay any substance dividend paid out of funds that accumulated
     prior to the Closing Date. In case the Purchaser is transferring the shares
     of the Company and to a third party, the Purchaser shall oblige the
     acquirer to observe this obligation.

     The Sellers, however, agree to such a transaction provided that the
     Purchaser submits a written confirmation by the competent tax authorities
     that the relevant transaction does not trigger any negative tax
     consequences for any of the Sellers.

                                   ARTICLE 5
                                   ---------
                                    Remedies
                                    --------

5.1  Term of Warranties and Representations. The representations and warranties
     --------------------------------------
     set forth in art. 3 and 4 of this Agreement shall continue in effect until
     the first anniversary of the Closing Date, except as otherwise specified in
     this Article. The representations and warranties set forth in art. 3.9
     shall continue in effect until the statute of limitation on the tax claims
     concerned has expired.

     The representations and warranties set forth in art. 4.4 of this Agreement
     shall
<PAGE>

     continue in effect for a period of 18 months as from the Closing Date and
     the representations and warranties set forth in art. 4.5 for a period of
     five years as from the Closing Date.

5.2  Waiver of Notification Requirement. The parties waive the notification and
     ----------------------------------
     examination requirements pursuant to Art. 201 of the Swiss Code of Obliga-
     tions, However, the Purchaser shall notify the Sellers within 60 days after
     the Purchaser has detected a breach of warranties, describing in reasonable
     detail such breach and any damages suffered by the Company as a result of
     such breach.

5.3  Remedies. In case of a breach of warranty or representation by the Sellers,
     --------
     Sellers shall restitute to the Purchaser the amount by which the actual
     situation of the Companies differs from the situation described in such
     warranty or representation provided, however, that each Seller shall only
     be liable for such a share in the amount due that corresponds to his share
     as set forth in Exhibit 5.3. The Purchaser shall be entitled to reduce the
                     -----------
     number of Future Shares to be handed over to each of the Sellers pursuant
     to art. 1.2 (ii) by reducing the amounts set out in Exhibit 1.2b in
                                                         ------------
     proportion to each Seller's share as set out in Exhibit 5.3.
                                                     -----------

     In case of a breach of warranty or representation by the Purchaser,
     Purchaser shall restitute to each Seller the amount by which his actual
     situation differs from the situation described in such warranty or
     representation.

5.4  Procedure with Third Parties and Authorities. If a breach of warranty
     --------------------------------------------
     exists because any authorities or other third parties raise claims against
     the Company or if the Company in connection with such a breach has to
     enforce any rights or claims against authorities or other third parties,
     such negotia-
<PAGE>

     tions and proceedings shall be carried on in consultation with the Sellers
     who may also take over such negotiations and proceedings and conduct them
     themselves for the account of the Company.

                                   ARTICLE 6
                                   ---------
                           Resignations of Directors
                           -------------------------

At the Closing Date, Sellers shall remit to Purchaser resignations of all the
directors of the Company. Such resignations shall contain a clause in which the
directors confirm that they have no claims against the Company.

Purchaser agrees to hold an extraordinary shareholders' meeting immediately
after the Closing Date and to elect new directors at such meeting. Purchaser
agrees to grant complete discharge to the present directors at such meeting for
their acts and decisions known or disclosed to Purchaser on or before the
Closing Date. The consent of the Purchaser to the Company's financial statements
and the discharge of the directors does not operate as a waiver of Purchaser's
claims under art. 3 of this Agreement.

                                   ARTICLE 7
                                   ---------
                                   Covenants
                                   ---------

7.1  Covenant not to Compete. The Sellers shall neither, for a period of two
     -----------------------
     years from the date hereof, accept any part or full time employment in any
     of the following companies:

     Plumtree, Epicentric, InfoImage, 2Bridge, Brio, Business Objects, Cognos,
     Hummingbird, Verano and/or Information Advantage (hereinafter referred to
<PAGE>

     as "Competitors")

     nor act as a consultant or representative of any Competitor.

7.2  Conduct of Business. The Sellers shall secure from the date hereof until
     -------------------
     the Closing:

     -  no significant action and decision (in particular, regarding investments
        and employment of managers) shall be taken without prior written
        approval of Purchaser; and

     -  the Company shall not change the terms and conditions of any material
        agreement or contract in which it is a party (all agreements contained
        in Exhibit 3.10 shall be considered as material),
           ------------

7.3  Termination of Agreements between the Companies and Sellers and among
     ---------------------------------------------------------------------
     Sellers. On or before the Closing Date, Sellers shall terminate all
     -------
     agreements existing between the Company and any Seller as well as any
     Shareholders agreements, except for the existing employment relationships
     between the Company and Messrs. Charles Fraefel and Chula de Silva. The
     termination of such agreement shall not oblige the Company to make any
     payments in compensation of termination such as severance payments or any
     payment for a notification period extending beyond the Closing Date.

                                   ARTICLE 8
                                   ---------
                                 Miscellaneous
                                 -------------

8.1  Cost. Each party bears the fees of its counsel and advisors. Purchaser
     ----
     shall,
<PAGE>

     however, bear all costs of Sellers' advisors and/or consultants directly
     related to the due diligence review and to the preparation of the Company's
     accounts under U.S. generally accepted accounting principles.

8.2  Notice. Any notice, request, instruction or other document deemed by either
     ------
     party to be necessary or desirable to be provided to the other party shall
     be in writing and shall be delivered by international overnight courier or
     via Facsimile as follows:

     If to Purchaser:                   Viador, Inc.
                                        Attn. Mr. Ben Connors
                                        167, Second Avenue
                                        San Mateo, CA 94401
                                        USA
                                        Fax + 1-650-685 3098

     With a copy to:                    Dr. Markus Guggenbuhl
                                        Pestalozzi Haegi & Partners
                                        Arterstrasse 24
                                        P.O. Box
                                        8032 Zurich
                                        Switzerland
                                        Fax + 41-1-254 34 10

     If to Sellers:                     Mr. Andreas Zwimpfer
                                        Riedsortstrasse 59
                                        6553 Weggis
                                        Switzerland
                                        Fax + 41-41-391 00 59

     With a copy to:                    Dr. Peter Reinert
                                        Baker & McKenzie
                                        Zollikerstrasse 225
                                        P.O. Box
                                        8034 Zurich
                                        Fax + 41-1 384 12 84
<PAGE>

     Each party may at any time change its address by giving notice to the other
     party in the manner described above.

8.3  No Waiver. The failure of any of the parties to enforce any of the
     ---------
     provisions of this Agreement, or any rights with respect thereto, shall in
     no way be considered as a waiver of such provisions or rights or in any
     way affect the validity of this Agreement. The waiver of any breach of
     this Agreement by any party, hereto shall not operate to be construed as a
     waiver of any other prior or subsequent breach.

8.4  Entire Agreement. This instrument embodies the entire agreement between the
     ----------------
     parties hereto with respect to the transaction contemplated herein and
     there have been and are no agreements or warranties between the parties
     other than those set forth or provided for herein. This agreement may be
     amended only in writing through a document signed by all the parties
     hereto.

8.5  Binding on Successors. All of the terms, provisions and conditions of this
     ---------------------
     Agreement shall be binding upon and inure to the benefit of the parties
     hereto and their respective heirs, successors, assigns and legal
     representatives.

8.6  Announcements. Sellers and Purchaser shall consult before issuing press
     -------------
     releases or otherwise making any public statements or any statements to the
     Company's employees with respect to this Agreement and shall not issue any
     such press release or statement without the prior approval of the other
     party. The parties shall not disclose any term of this Agreement to any
     third parties without the explicit consent of the other party.

8.7.  Counterparts. This Agreement may be executed in counterparts.
      ------------
<PAGE>

                                   ARTICLE 9
                                   ---------
                     Transfer of Management Responsibility
                     -------------------------------------

As of the Closing Date, Purchaser takes over full responsibility for the
Company's management and operations.

                                   ARTICLE 10
                                   ----------
                         Governing Law and Arbitration
                         -----------------------------

10.1  Governing Law. This Agreement shall be subject to and governed by Swiss
      -------------
      Law with the exception of the UN Convention on the International Sale of
      Goods of April 11, 1980.

10.2  Arbitration. All disputes arising out of or in connection with this
      -----------
      agreement, including disputes on its conclusion, binding effect, amend-
      ment or termination, shall be resolved, to the exclusion of the ordinary
      courts, by an Arbitral Tribunal in Zurich in accordance with the Inter-
      national Arbitration Rules of the Zurich Chamber of Commerce.
<PAGE>

IN WITNESS WHEREOF, the parties thereto have executed this agreement as of this
January 20, 2000.

Sellers:                      Purchaser:
                              Viador, Inc.

/s/ Andreas Zwimpfer          /s/ Ben Connors
--------------------          ---------------
Andreas Zwimpfer              By: Ben Connors
                              Its: Vice President, Business Development and
                              International

/s/ David Keat
--------------
David Keat



/s/ Charles Fraefel
-------------------
Charles Fraefel



/s/ Chula de Silva
------------------
Chula de Silva



/s/ Tim Moser
-------------
Tim Moser
<PAGE>

                                 Exhibit 1.2a

On the Closing Date, the Purchaser shall pay to each of the Sellers the amount
set out next to, such Seller:

Andreas Zwimpfer                                        USD 250'000
David Keat                                              USD 250'000
Charles Fraefel                                         USD 250'000
Chula de Silva                                          USD 150'000
Tim Moser                                               USD 100'000
<PAGE>

                                  Exhibit 1.2b

Each of the Sellers shall receive such number of Future Shares corresponding to
the following amounts set next to his name:

Andreas Zwimpfer                                        USD 250'000
David Keat                                              USD 250'000
Charles Fraefel                                         USD 250'000
Chula de Silva                                          USD 150'000
Tim Moser                                               USD 100'000
<PAGE>

                                  Exhibit 4.3

If Purchaser elects to pay its indebtedness in accordance with Art 1.2(b) in
Future Shares, said future shares shall be Registered; as such, Purchaser shall
be required to and be responsible for registering said Future shares in
accordance with U.S. law and any applicable state laws.
<PAGE>

                                  Exhibit 5.3

Liability of Sellers


Andreas Zwimpfer                                          25%
David Keat                                                25%
Charles Fraefel                                           25%
Chula de Silva                                            15%
Tim Moser                                                 10%
<PAGE>

                                     Index



1. Articles of Incorporation and organizational regulations of the Company.
   (Exhibit 3.1)

2. Minutes of Shareholders' Meetings and Directors' Meetings of the Company.
   (Exhibit 3.4)

3. Financial Statements.
   (Exhibit 3.5)

4. Agreements with Third Parties.
   (Exhibit 3.10)

5. Intellectual Property/Domain Names/Know-how.
   (Exhibit 3.11)

6. Insurance Policies.
   (Exhibit 3.13)

7. Arbeitsvertrage
   (Exhibit 3.12)
<PAGE>

                          ORAGANIZATIONAL REGULATIONS

                                       of

                                   Viador AG

                                       in

                                 Baden-Dattwil

________________________________________________________________________________


Art. 1:  Statutory Basis
-------  ---------------

These Regulations are enacted by the Board of Directors in accordance with Arti-
cle 716b para. 2 of the Swiss Code of Obligations and Article 14 para. 2 of the
Articles of Incorporation of the Company.

The purpose of the Regulations is to define the executive powers within the Com-
pany and to delegate part of the responsibilities and powers of the Board of Di-
rectors to the Management of the Company.


Art. 2:  Executive Bodies of the Company
-------  -------------------------------

The Company has the following executive bodies:

1.  The Board of Directors

2.  The Management


Art. 3:  Relationship with Viador Inc.
-------  -----------------------------

The Company is a wholly owned subsidiary of Viador Inc., San Mateo, USA. In or-
der to ensure efficient group management, the Board of Directors of Viador Inc.
will issue directives as may be necessary from time to time. The Company shall
comply with those directives as long as they are not in violation with any
legal, statutory or other provisions as may be applicable in Switzerland or
elsewhere.

The parent company Viador Inc. shall delegate at least one representative to the
Board of Directors of the Company who shall inform the Company of all group ac-
tivities and other important affairs, thereby enabling the Board of Directors to
fulfill its legal duties and obligations.
<PAGE>

Art. 4:  Board of Directors
-------  ------------------

4.1  Organization

The Board of Directors elects from its members the Chairman and the Delegate
(Managing Director). The Board of Directors may appoint, as the case may be, a
Vice-Chairman. It may also appoint a secretary who does not necessarily have to
be a member of the Board.

4.2  Meetings

The Board of Directors shall convene as often as the business and affairs of the
Company require a meeting and whenever it is requested by one of its members,
but at least once a year.

It shall be necessary to give not less than ten days' notice of a meeting of the
Board of Directors to each director unless he otherwise agrees in writing or by
telex of by such other means as the Board may approve.

The meetings may also be held in the United States.

4.3  Resolutions

Board resolutions are taken by the majority of the votes of the directors
present and each resolution requires the affirmative vote of the Chairman except
if the Chairman sends a written waiver of participation to the Company. There is
no minimum quorum required.

4.4  Circular Resolutions and Other Forms of Resolutions

If a written proposal for a resolution has been submitted, the resolution may be
taken by circular letter, telefax or telegram, unless a director demands a
discussion in a formal meeting. A resolution by circular letter shall require
the approval of the majority of all the members of the Board of Directors,
including the Chairman of the Board of Directors.

Resolutions may also be taken by way of a telephone or video conference, unless
a director requests a discussion in a formal meeting. Resolutions by telephone
or video conference shall be minuted in accordance with Article 4.5.

4.5.  Minutes

The meetings of the Board and the resolutions taken by the Board shall be
minuted. Such minutes shall in particular contain the declarations made by any
one member with the request to be minuted as well as all the resolutions.

The Minutes shall be signed by the Chairman of the meeting and the secretary.
<PAGE>

4.6   Information

Any member of the Board of Directors may request information about all the mat-
ters concerning the Company.

At meetings, all board members as well as all persons responsible for manage-
ment are required to provide the information requested. Outside meetings, each
Board member has the right to request information from the persons responsible
for the management regarding the general business affairs and, with the approval
of the Chairman, also regarding particular business transations.

4.7   Powers of the Board of Directors

The Board of Directors shall have the following non-transferable and inalienable
duties:

(i)   The ultimate management of the Company and the giving of the necessary
      directives;

(ii)  The establishment of the organization;

(iii) The structuring of the accounting system and the financial controls as
      well as the financial planning necessary to manage the Company;

(iv)  The appointment and removal of the persons entrusted with the general
      management and the representation of the Company, as well as the signa-
      tory power of such persons;

(v)   The ultimate supervision of the persons authorized to manage the Com-pany,
      in particular, in view of compliance with the law, the Articles of Incor-
      poration, these Regulations and the Board directives;

(vi)  The preparation of the business report as well as the preparation of the
      general meeting of shareholders and the implementation of its resolutions;

(vii) The notification of the judge in the case of overindebtedness of the
      Company.


Art. 5:  Delegation of the Management
-------  ----------------------------

The Management of the Company shall consist of the Managing Director and the
Managers. The Management shall constitute itself and set up its own
organization. The Board of Directors fully delegates all powers it has to manage
the affairs of the Company to the extent the management is not by law reserved
to the Board of Directors (Art. 716a CO). In particular, the Management shall
implement the business policies of the Company as defined by the Board and
manage the day-to-day business of the Company.
<PAGE>

Art. 6:  Reporting
-------  ---------

In each meeting of the Board of Directors the management informs the Board on
the state of affairs of the Company so as to allow the Board of Directors to
comply with its statutory duty to ultimately manage and supervise the Company.
In particular, once a year the management provides the Board of Directors with
a comprehensive business report. If deemed necessary or appropriate, the
managing director may request the participation of other officers.

At any time, the Management shall report without delay to the Board of Directors
all significant changes, developments and other events affecting the business of
the Company.

Art. 7:  Miscellaneous
-------  -------------

7.1  Effectiveness

These Regulations shall become effective as of January [  ] 2000.

7.2  Modifications and Amendments

Modifications and amendments of these Regulations require a resolution of the
Board of Directors to be taken by a unanimous vote of all of the members of the
Board of Directors.


Place and date:


The Chairman of the Board:



---------------------
Ben Connors
<PAGE>

                                    MINUTES


            of the Extraordinary General Meeting of the Shareholders

                                       of

                                   Viador AG

                                       in

                                 Baden-Dattwil

                               held on [  ] 2000,

at the offices of Pestalozzi Haegi & Partners, Arterstrasse 24, CH-8032 Zurich

________________________________________________________________________________

Mr. Ben Connors opens the meeting and takes the chair. Dr. Markus Guggenbuhl
acts as secretary and scrutineer.

No objection is made against the form, place or date for which this meeting is
called. The Chairman states that all shares of the Company are represented at
the meeting and that today's Extraordinary General Meeting of the Shareholders
is therefore validly constituted as a universal meeting within the meaning of
Art. 701 of the Swiss Code of Oligations.

No objection is raised against these statements by any person present.



I.   AGENDA


1.   Resignation and Discharge of Members of the Board of Directors


2.   Election of Members of the Board of Directors


                               ******************
<PAGE>

II.  MINUTES OF THE MEETING


1.   Resignation of two Members of the Board of Directors

     The general meeting of shareholders takes note of the resignation of
     Messrs. Charles Zwimpfer and David Keat from the Board of Directors and
     resolves to discharge both of them for their services rendered to the
     Company to the extent such services are known or were disclosed to the
     shareholders.

2.   Election of new Member of the Board of Directors

     The general meeting of shareholders elects Messrs. Ben Connors, San Mateo,
     USA, and Dr. Markus Guggenbuhl, Meilen, as a new members of the Board of
     Directors.

     (Deutsche Ubersetzung: Die Generalversammlung wahlt die Herren Ben Connors,
     San Mateo, USA, und Dr. Markus Guggenbuhl, Meilen, neu in den
     Verwaltungsrat)


The meeting is closed at []


January [  ], 2000


The Chairman:                       The Secretary and Scrutineer:


---------------------               ------------------------------
Ben Connors                         Dr. Markus Guggenbuhl
<PAGE>

                              CIRCULAR RESOLUTION

                          of the Board of Directors of

                                   Viador AG

                                 Baden-Dattwil

                          dated as of January 20, 2000


The undersigned, being all of the Directors of Viador AG, Baden-Dattwil, hereby
waive to require a meeting and approve, consent to and unanimously adopt the
following resolution:

                                    AGENDA:
                                    -------


1.  Adoption of the organisational regulations

                                      ***

1.   The Board further resolves to adopt the organisational regulations as at-
     tached in Annex 1 hereto.
<PAGE>

                               ZIRKULARBESCHLUSS

                            des Verwaltungsrates der

                                   Viador AG

                                 Baden-Dattwil

                              per 20. January 2000

________________________________________________________________________________

Die unterzeichnenden Mitglieder des Verwaltungsrates der Viador AG, Baden-
Dattwil, verzichten hiermit auf die Einberufung einer Sitzung und fassen
einstimmig folgenden Beschluss:


                                  TRAKTANDUM:
                                  -----------


1.   Annahme des Organisationsreglements

                                      ***

1.   Der Verwaltungsrat beschliesst, das Organisationsreglement gemass Anhang 1
     zu diesem Beschluss anzunehmen.
<PAGE>

__________________                   ___________________________
Ben Connors                          Charles Fraefel



_________________________
Dr. Markus Guggenbuhl