<PAGE>   1
                                                                   EXHIBIT 10.49


THIS SECURED PROMISSORY NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933, AS AMENDED, OR ANY STATE SECURITIES LAWS (COLLECTIVELY, THE "ACTS"), AND
MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, ASSIGNED OR DISPOSED OF
EXCEPT PURSUANT TO REGISTRATION UNDER SUCH ACTS OR UNLESS THE CORPORATION HAS
RECEIVED AN OPINION OF COUNSEL, OR OTHER EVIDENCE REASONABLY SATISFACTORY TO THE
CORPORATION, THAT SUCH REGISTRATION IS NOT REQUIRED.


                             SECURED PROMISSORY NOTE


$8,000,000.00                      Orem, Utah                    _________, 2001


                  FOR VALUE RECEIVED, the undersigned, Caldera International,
Inc., a Delaware corporation ("Borrower"), promises to pay to The Santa Cruz
Operation, Inc., a California Corporation ("Lender"), the sum of Eight Million
Dollars ($8,000,000.00) in lawful money of the United States of America. Other
than as provided below with respect to past due principal amounts, no interest
shall accrue or be payable under this promissory note (this "Note"). Subject to
applicable deductions described below, the principal of this Note shall be due
and payable in four consecutive quarterly installments of $2 million each, with
the first such installment due on the first day of the fifth, full Caldera
Fiscal Quarter following the Effective Date. This note is a full recourse note
with respect to the Borrower.

                  All terms not otherwise defined herein shall have the meanings
ascribed to them in that certain Agreement and Plan of Reorganization, dated
August 1, 2000, among the Lender, the Borrower and Caldera Systems, Inc. (as
amended, the "Reorganization Agreement").

                  Payment of this Note is secured by a Security Agreement
executed on this date by Borrower and covering all of the assets of Borrower
relating to Borrower's OpenServer Business. If action is instituted to collect
this note, the Borrower promises to pay all costs and expenses, including
reasonable attorneys' fees, incurred in connection with such actions.

                  All past due principal and accrued interest on this Note shall
bear interest from maturity until paid at the lesser of (i) the rate of 10% per
annum or (ii) the highest rate for which Borrower may legally contract under
applicable law. All payments on past due principal and accrued interest
hereunder shall be payable in lawful money of the United States of America which
shall be legal tender for public and private debts at the time of payments.

1. Right of Offset and Reduction. The principal amount of this Note shall be
reduced by an amount (the "Reduction Amount") equal to the sum of (i) all Commit
Transaction Receivables for which payment has not been received prior to the
one-year anniversary of the Effective Time, plus (ii) 50% of Borrower's costs
(excluding internal, employee costs) in collecting Commit Transaction
Receivables during the period beginning on the Effective Time

<PAGE>   2

and ending on the one-year anniversary of the Effective Time; provided that if
Borrower forgives payment under or replaces any Commit Transaction Receivables
without Lender's consent, no deduction relating to the non-payment of such
forgiven or replaced Commit Transaction Receivables will be allowed. Borrower
agrees to use commercially reasonable business practices in collecting the
Commit Transaction Receivables. The Reduction Amount shall be applied first
against the initial installment payment under this Note and then, to the extent
necessary, shall be applied against the second, third and/or fourth installment
payments, in that order.

2. Prepayments. This Note may be prepaid by Borrower in whole or in part without
the consent of the holder and without prepayment penalty of any kind.

3. Default; Remedies. The entire unpaid balance of this Note shall be
immediately due and payable at the option of the holder hereof upon the
occurrence of an Event of Default. For the purposes of this Agreement, an Event
of Default shall have occurred if (i) the Borrower shall have materially failed
to perform any covenant or other obligation hereunder, and such failure shall
have continued for twenty (20) days after Borrower shall have received notice
thereof, (ii) the Borrower shall commence a voluntary case or other proceeding
seeking liquidation or other reorganization with respect to itself or its debts
under any bankruptcy, insolvency or other similar law now or hereafter in effect
or seeking the appointment of a trustee, receiver, liquidator, custodian or
other similar official of it or any substantial part of its property, or shall
make a general assignment for the benefit of creditors, or shall fail generally
to pay its debts as they become due; or (iii) an involuntary case or other
proceeding shall be commenced against the Borrower seeking liquidation,
reorganization or other relief with respect to it or its debts under any
bankruptcy, insolvency or other similar law now or hereafter in effect or
seeking the appointment of a trustee, liquidator, receiver, custodian or other
similar official of it or any substantial part of its property, and such
involuntary case or other proceeding shall remain undismissed and unstayed for a
period of 90 consecutive days.

4. No Waiver; Cumulative Rights. No delay on the part of the holder of this Note
in the exercise of any power or right under this Note or under any other
instrument executed pursuant hereto shall operate as a waiver thereof, nor shall
a single or partial exercise of any power or right preclude other or further
exercise thereof or the exercise of any other power or right.

6. Waiver. Borrower and all endorsers, sureties and guarantors of this Note
waive demand, presentment, protest, notice of dishonor, notice of nonpayment,
notice of intention to accelerate, notice of acceleration, notice of protest and
any and all lack of diligence or delay in collection or the filing of suit
hereon which may occur, and agree to all extensions and partial payments, before
or after maturity, without prejudice to the holder hereof.

7. Collection Costs. In the event that, upon an Event of Default, any amount
under this Note is collected in whole or in part through suit, arbitration or
mediation, then and in any such case there shall be added to the unpaid
principal balance hereof all costs of collection, (including, but not limited
to, reasonable attorneys' fees and expenses) whether or not suit is filed.

8. Governing Law. This Note shall be governed by and construed in accordance
with the laws of the State of California.


                                       2
<PAGE>   3

9. Venue. The parties agree that any dispute regarding the interpretation or
validity of, or otherwise arising out of this Note, shall be subject to the
exclusive jurisdiction of the California State Courts in and for Santa Clara
County, California or, in the event of federal jurisdiction, the United States
District Court for the Northern District of California sitting in Santa Clara
County, California, and each party hereby agrees to submit to the personal and
exclusive jurisdiction and venue of such courts and not to seek the transfer of
any case or proceeding out of such courts.

10. Headings. The headings of the sections of this Note are inserted for
convenience of reference only and shall not be deemed to constitute a part
hereof.

11. Usury. All agreements between Borrower and the holder of this Note, whether
now existing or hereafter arising and whether written or oral, are expressly
limited so that in no contingency or event whatsoever, whether by acceleration
of the maturity of this Note or otherwise, shall the amount paid, or agreed to
be paid, to the holder hereof for the use, forbearance or detention of the money
to be loaned hereunder or otherwise, exceed the maximum amount permissible under
applicable law. If from any circumstances whatsoever fulfillment of any
provision of this Note or of any other document evidencing, securing or
pertaining to the indebtedness evidenced hereby, at the time performance of such
provision shall be due, shall involve transcending the limit of validity
prescribed by law, then ipso facto, the obligation to be fulfilled shall be
reduced to the limit of such validity, and if from any such circumstances the
holder of this Note shall ever receive anything of value as interest or deemed
interest by applicable law under this Note or any other document evidencing,
securing or pertaining to the indebtedness evidenced hereby or otherwise an
amount that would exceed the highest lawful rate, such amount that would be
excessive interest shall be applied to the reduction of the principal amount
owing under this Note or on account of any other indebtedness of Borrower to the
holder hereof relating to this Note, and not to the payment of interest, or if
such excessive interest exceeds the unpaid balance of principal of this Note and
such other indebtedness, such excess shall be refunded to Borrower. In
determining whether or not the interest paid or payable with respect to any
indebtedness of Borrower to the holder hereof, under any specific contingency,
exceeds the highest lawful rate, Borrower and the holder hereof shall, to the
maximum extent permitted by applicable law, (i) characterize any nonprincipal
payment as an expense, fee or premium rather than as interest, (ii) amortize,
prorate, allocate and spread the total amount of interest throughout the full
term of such indebtedness so that the actual rate of interest on account of such
indebtedness is uniform throughout the term thereof, and/or (iii) allocate
interest between portions of such indebtedness, to the end that no such portion
shall bear interest at a rate greater than that permitted by law. The terms and
provisions of this paragraph shall control and supersede every other conflicting
provision of all agreements between Borrower and the holder hereof.

12. Successors and Assigns. All of the stipulations, promises and agreements in
this Note made by or on behalf of Borrower shall bind the successors and assigns
of Borrower, whether so expressed or not, and inure to the benefit of the
successors and assigns of Borrower and Lender. Any assignee of Borrower or
Lender shall agree in writing prior to the effectiveness of such assignment to
be bound by the provisions hereof. Borrower shall not assign this Note or any of


                                       3
<PAGE>   4

its rights, interests or obligations under this Note to any third party, other
than by operation of law, without Lender's written consent, which shall not be
unreasonably withheld.

13. Severability. In the event any one or more of the provisions contained in
this Note shall for any reason be held to be invalid, illegal or unenforceable
in any respect, such invalidity, illegality or unenforceability shall not affect
any other provision hereof, and this Note shall be construed as if such invalid,
illegal or unenforceable provision had never been contained herein.

14. Notices. All notices and other communications hereunder shall be in writing
or by telex, telegram or telecopy, and shall be deemed to have been duly made
when delivered in person or sent by telex, telegram, telecopy, same day or
overnight courier, or 72 hours after having been deposited in the United States
first class or registered or certified mail return receipt requested, postage
prepaid, to a party at the address set forth below (which may be changed in
accordance with these notice procedures):

         If to Lender:

                  The Santa Cruz Operation, Inc.
                  425 Encinal
                  Santa Cruz, California 95061-1900
                  Attention: Law and Corporate Affairs
                  Fax:  (831) 427-5454

         with a copy (which shall not constitute notice) to:

                  Wilson Sonsini Goodrich & Rosati
                  650 Page Mill Road
                  Palo Alto, CA 94304-1050
                  Attention: Michael Danaher
                  Fax:  (650) 493-6811

         If to Borrower:

                  Caldera Systems, Inc.
                  240 West Center Street
                  Orem, Utah 84057
                  Attention: Chief Executive Officer
                  Fax:  (801) 765-1313

         with a copy (which shall not constitute notice) to:

                  Brobeck, Phleger & Harrison LLP
                  370 Interlocken Boulevard, Suite 500
                  Broomfield, Colorado 80021
                  Attention: John E. Hayes, III
                  Fax: (303) 410-2199



                                       4
<PAGE>   5

                  IN WITNESS WHEREOF, the undersigned has executed this Secured
Promissory Note on and as of the date first set forth above.

                                        CALDERA INTERNATIONAL, INC.


                                        By:
                                            ------------------------------------


AGREED AND ACCEPTED:

THE SANTA CRUZ OPERATION, INC.



By:
    --------------------------------


                                       5