<PAGE>
 
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D. C. 20549

                                    FORM 10-Q

(Mark One)

[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
     ACT OF 1934

For the quarterly period ended September 27, 1998
                               ------------------

                                       OR

[ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES
     EXCHANGE ACT OF 1934 

      For the transition period from ___________________to ______________

Commission file number 012378
                       ------

                              CARLETON CORPORATION
             ------------------------------------------------------
             (Exact name of registrant as specified in its charter)

        Minnesota                                      41-1349953
-------------------------------       -----------------------------------------
(State or other jurisdiction of       (I. R. S. Employer Identification Number)
incorporation or organization)

        10729 Bren Road East, Minnetonka, Minnesota            55343
        -------------------------------------------            -----
         (Address of principal executive offices)            (Zip Code)

Registrant's telephone number, including area code  (612) 238-4000
                                                    --------------

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15 (d) of the Securities Exchange Act of 1934
during the preceding 12 months (or for such shorter period that the registrant
was required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

                                 Yes [X] No [ ]

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date.

Common Stock, $.25 par value                        3,343,266           
----------------------------           --------------------------------------
         Class                         Shares outstanding on October 31, 1998
<PAGE>
 
Part  I.  FINANCIAL INFORMATION

          ITEM  1. FINANCIAL STATEMENTS

          Consolidated Statement of Operations - Three and Six Months
          Ended September 27, 1998 and September 28, 1997...............  1

          Consolidated Balance Sheets - September 27, 1998 and
          March 29, 1998................................................  2

          Consolidated Statements of Cash Flows - Six Months Ended
          September 27, 1998 and September 28, 1997.....................  3

          Notes to Financial Statements.................................  4

          ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                  CONDITION AND RESULTS OF OPERATIONS

          Liquidity and Capital Resources...............................  5

          Results of Operations.........................................  5

PART II.  OTHER INFORMATION

          ITEM 1.  LEGAL PROCEEDINGS....................................  7

          ITEM 2.  CHANGES IN SECURITIES................................  7

          ITEM 3.  DEFAULTS UPON SENIOR SECURITIES......................  7

          ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF
                   SECURITY HOLDERS.....................................  7

          ITEM 5.  OTHER INFORMATION....................................  7

          ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K.....................  7
<PAGE>
 
PART I.  FINANCIAL INFORMATION

Item 1.  Financial Statements

CONSOLIDATED STATEMENTS OF OPERATIONS
(Dollars in Thousands, Except Per Share Amounts)

<TABLE>
<CAPTION>

                                                       Three Months Ended     Six Months Ended
                                                      ---------------------  ------------------
                                                      Sept 27,     Sept 28,  Sept 27,  Sept 28,
                                                        1998        1997      1998      1997
                                                      -----------------------------------------
<S>                                                   <C>        <C>        <C>        <C>    
Revenues
   Sales                                              $   513    $   433    $ 1,428    $   624
   Maintenance and Other                                  499        103        906        191
                                                      -------    -------    -------    -------
   Total                                                1,012        536      2,334        815

Costs and Expenses
   Cost of revenues                                       671        418      1,297        857
   Research, development and engineering                  942        492      1,903        981
   Selling, general and administrative                  1,487        977      2,995      1,908
                                                      -------    -------    -------    -------
   Total                                                3,100      1,887      6,195      3,746
                                                      -------    -------    -------    -------
Loss from operations                                   (2,088)    (1,351)    (3,861)    (2,931)

Investment income                                         108        109        260        236
Interest expense and other                                (15)       (37)       (31)       (34)
                                                      -------    -------    -------    -------

Loss from continuing operations before income taxes    (1,995)    (1,279)    (3,632)    (2,729)
Income taxes                                                0          3          0          5
                                                      -------    -------    -------    -------
Net loss from continuing operations                    (1,995)    (1,282)    (3,632)    (2,734)

Discontinued operations:
   Income from operations of discontinued
     Internet Solutions Division                            0        303          0      1,228
                                                      -------    -------    -------    -------

Net Loss                                              $(1,995)   $(  979)   $(3,632)   $(1,506)
                                                      =======    =======    =======    =======

Income (Loss) per Share:
   Continuing Operations                              $( 0.60)   $( 0.45)   $( 1.09)   $( 0.96)
   Discontinued Operations                               0.00       0.11       0.00       0.43
                                                      -------    -------    -------    -------
   Total                                              $( 0.60)   $( 0.34)   $( 1.09)   $( 0.53)
                                                      =======    =======    =======    =======

Weighted Average Shares Outstanding                     3,343      2,846      3,333      2,839
                                                      =======    =======    =======    =======
</TABLE>

See accompanying Notes to Financial Statements.
<PAGE>
 
CONSOLIDATED BALANCE SHEETS
(Dollars in Thousands)

<TABLE>
<CAPTION>

                                                                    (Unaudited)
                                                                    September 27, March 29,
                                                                       1998         1998
                                                                    -----------------------
ASSETS
<S>                                                                  <C>         <C>     
Current Assets
   Cash and cash equivalents                                         $  7,764    $ 11,111
   Cash in escrow                                                          61         730
   Accounts receivable - net                                              628       1,517
   Other                                                                  150          76
                                                                     --------    --------
   Total current assets                                                 8,603      13,434

Property and equipment                                                  4,313       4,649
Accumulated depreciation                                               (3,080)     (3,256)
                                                                     --------    --------
Property and equipment - net                                            1,233       1,393
                                                                     --------    --------

                                                                     $  9,836    $ 14,827
                                                                     ========    ========


LIABILITIES AND SHAREHOLDERS' EQUITY

Current Liabilities
   Accounts payable                                                  $    366    $    319
   Accrued expenses                                                     1,816       3,067
   Deferred revenue                                                       695         809
   Note payable                                                         1,000       1,000
                                                                     --------    --------
   Total current liabilities                                            3,877       5,195

Long-term Notes Payable                                                   506         602

Shareholders' Equity
   Common stock - authorized, 6,000,000 shares at $.25 par value;
   issued and outstanding at September 27, 1998 - 3,343,266 shares
   March 29, 1998 - 3,305,363 shares                                      836         826
   Additional paid-in capital                                          62,768      62,723
   Retained deficit                                                   (58,151)    (54,519)
                                                                     --------    --------
   Total shareholders' equity                                           5,453       9,030
                                                                     --------    --------

Total                                                                $  9,836    $ 14,827
                                                                     ========    ========
</TABLE>


See accompanying Notes to Financial Statements.
<PAGE>
 
CONSOLIDATED STATEMENTS OF CASH FLOWS
(Dollars in Thousands)
(Unaudited)

<TABLE>
<CAPTION>

                                                                          Six Months Ended
                                                                       ---------------------
                                                                        Sept 27,   Sept 28,
                                                                          1998       1997
                                                                       ---------------------
<S>                                                                    <C>         <C>      
Operating Activities:
   Net loss                                                            $( 3,632)   $( 1,506)
   Adjustments to reconcile net loss to net cash used in operations:
   Depreciation and amortization                                            221       1,070
   Accounts receivable                                                      889         892
   Installment receivables                                                    0         272
   Inventory                                                                  0          20
   Other assets                                                             (74)         13
   Accounts payable, accrued expenses and deferred revenue               (1,318)     (4,514)
                                                                       --------    --------
   Net cash flows used in operating activities                           (3,914)     (3,753)

Investing Activities:
   Purchases of property and equipment (net)                                (61)        (47)
   Change in cash held in escrow                                            669         (20)
                                                                       --------    --------
   Net cash flows from (used in) investing activities                       608         (67)

Financing Activities:
   Repayments of debt                                                       (96)          0
   Stock options/restricted stock activity (net)                             55         157
                                                                       --------    --------
   Net cash flows from (used in) financing activities                       (41)        157
                                                                       --------    --------

Net decrease in cash and cash equivalents                                (3,347)     (3,663)
Beginning cash and cash equivalents                                      11,111      13,865
                                                                       --------    --------
Ending cash and cash equivalents                                       $  7,764    $ 10,202
                                                                       ========    ========

Supplemental disclosures of cash flow information:
   Cash paid for interest                                              $     39    $     26
   Cash paid for income taxes                                                 9          32
</TABLE>

See accompanying Notes to Financial Statements.
<PAGE>
 
                          NOTES TO FINANCIAL STATEMENTS
                                   (Unaudited)



1. MANAGEMENT REPRESENTATION AND NAME CHANGE

The accompanying unaudited interim financial statements have been prepared in
accordance with the instructions to Form 10-Q and do not include all the
information and footnotes required by generally accepted accounting principles
for complete financial statements. In the opinion of management, all adjustments
(consisting of normal recurring accruals) considered necessary for a fair
presentation have been included. The results of operations for any interim
period are not necessarily indicative of results for the year. These statements
should be read in conjunction with the financial statements and related notes
included in the Company's Annual Report on form 10-K for the year ended March
29, 1998.

The Company changed its name from Apertus Technologies Incorporated to Carleton
Corporation effective August 1, 1998. The Company's common stock continues to
trade on NASDAQ but the symbol changed from "APTS" to "CARL".

2. REVERSE STOCK SPLIT

The Company underwent a one-for-five reverse stock split effective with the
close of business on September 15, 1998. The reverse split was undertaken to
remain in compliance with NASDAQ's requirements for continued listing on the
National Market. All prior year comparative information has been adjusted to
give effect to the reverse stock split. The Company's trading symbol was changed
to "CARLD" for 20 trading days after the split. On October 14, 1998, the symbol
reverted back to "CARL".

3. DISCONTINUED OPERATIONS

The operating results of the Internet Solutions Division for the three and six
months ended September 28, 1997 have been reflected as discontinued operations
in the Consolidated Statement of Operations. The Internet Solutions Division was
sold to Computer Network Technology Corporation in October 1997 as previously
reported by the Company in Form 10-Q's and in Form 10-K for the year ended March
28, 1998.
<PAGE>
 
4. PRO FORMA RESULTS

The Company acquired a Massachusetts corporation then also known as "Carleton
Corporation" in October 1997. The transaction was accounted for under the
purchase method of accounting and the operating results of the former "Carleton
Corporation" has been included with the consolidated results subsequent to the
acquisition.

Pro forma consolidated results of continuing operations for the three and six
months ended September 28, 1997 as if "Carleton Corporation" had been acquired
at the beginning of fiscal 1997 are:

                                  Three Months         Six Months
                                  ------------         ----------
       Revenues                     $ 1,559             $ 2,527
       Net loss                      (1,924)             (4,058)
       Net loss per share              (.59)              (1.24)


5. NET LOSS PER SHARE

Net loss per share is computed using the weighted average number of common stock
shares outstanding during the applicable period. There is no impact to the
calculation of the net loss per share resulting from adoption of Financial
Accounting Standards Board Statement No. 128, "Earnings Per Share."
<PAGE>
 
ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
         AND RESULTS OF OPERATIONS

CAUTIONARY STATEMENT FOR PURPOSES OF THE "SAFE HARBOR" PROVISIONS OF THE PRIVATE
SECURITIES LITIGATION REFORM ACT OF 1995

This Quarterly Report on Form 10-Q contains forward-looking statements within
the meaning of the Private Securities Litigation Reform Act of 1995. These
forward-looking statements involve risks and uncertainties that may cause the
Company's actual results to differ materially from the results discussed in the
forward-looking statements. Factors that might cause such differences include,
but are not limited to, the following: market acceptance risk and decreased
demand for the Company's products; heightened competition; risk of technological
obsolescence of the Company's products; failure to obtain new customers or
retain existing customers; problems with software programs; risks associated
with the Company's dependence on proprietary technology, including those related
to adequacy of copyright, trademark and trade secret protection; inability to
resolve Year 2000 issues; integration of operations concerns; inability to
attract and retain key personnel resources; risks associated with single sources
of supply for certain components used in the Company's products; longer sales
cycles; inability to manage cost structure; inability to manage cost structure
inability to carry out sales and marketing plans and changes in interest rates.
The forward-looking statements herein are qualified in their entirety by the
cautions and risk factors set forth under "Cautionary Statement" filed as
Exhibit 99 to this Quarterly Report on Form 10-Q.

LIQUIDITY AND CAPITAL RESOURCES

The consolidated balance sheet at September 27, 1998, shows net working capital
of $4,725 including cash and cash equivalents of $7,764. The Company currently
anticipates minimal capital expenditures in the near future. These expenditures
will be primarily for the purchase of computers for any new hires. The Company
believes the cash position will be adequate to support its anticipated short-
term operating losses, make capital investments and fund working capital needs
into fiscal 1999-2000. The Company currently does not have any outside credit
arrangements other than a $1 million note that is secured by investments. The
Company will need to achieve profitability and generate positive cash flow in
fiscal 1999-2000 and beyond to meet its expected future operating and capital
cash needs.

RESULTS OF OPERATIONS

The consolidated statements of operations reflect discontinued operations (see
Note 3 to the financial statements) by showing the operating results of the
Internet Solutions Division as a single line item.

The consolidated statements of operations for the three and six months ended
September 27, 1998 include the results of the former "Carleton Corporation"
which was acquired by the Company in October 1997 (see Note 3 to the financial
statements).

Revenues for the three months ended September 27, 1998 reflect a significant
increase over the historical revenues from the same period in the prior year but
reflect a decrease of $293 from the pro forma revenues for the same period in
the prior year. Note that the prior year pro forma revenues included
approximately $170 of funded development and $437 more in license revenue. The
revenues were below the Company's expectations (due primarily to lower license
<PAGE>
 
revenues) and resulted in an operating loss that was higher than planned. The
costs and expenses were lower than planned due to lower headcount and lower
sales and professional services expenses that more than offset increased
marketing costs relating to advertising. The increased costs compared to the
historical level of similar costs in the prior year resulted primarily from the
additional costs of adding the former "Carleton Corporation" infrastructure. The
Company expects its revenues to increase in the coming quarters so that the
losses become smaller until the Company again achieves profitability. The
Company plans to continue to invest in development and engineering to make
product enhancements to increase functionality, product integration and to
address ease of use issues. Additional investment will also be made in expanding
business partner relationships, implementing marketing programs and increasing
market image and awareness of the Company's Pure View suite of products.

During the current quarter, the Company continued to make progress as an early
stage company. Although revenues were below expectations, the Company
accomplished the following: expand its business partner base, continue to
provide quality implementation services on significant projects for its
customers, establish reference accounts, improve product performance through
increased functionality and features, and increase its marketing promotion and
clarify its market position. The focus going forward will be to continue to
improve its products and to build sales momentum through its sales force,
broaden business partner alliance programs and continue to increase marketing
promotion and awareness. The Company is focused on becoming the market leader
for customer data repositories.

YEAR 2000

Many currently installed computer systems and software are coded to accept only
two-digit entries in the date code fields. These date code fields will need to
accept four-digit entries to distinguish 21st century dates from 20th century
dates. This problem could result in system failures or miscalculations causing
disruptions of business operations. The various software packages that the
Company uses for internal processing and to support its operations are obtained
from outside vendors. These software packages are Year 2000 compliant or are
expected to be Year 2000 compliant in the near future and made available to the
Company under maintenance contracts. The Company is also assessing Year 2000
compliance issues with companies with which it has third party outsourcing
relationships, such as banks, insurance companies, payroll processors and
telecommunications providers.

The Company believes that the products it sells are Year 2000 compliant. The 
Company has developed a comprehensive suite of Year 2000 tests and continues 
with its internal testing against those tests. The Company currently does not 
anticipate significant problems in achieving Year 2000 compliance with respect 
to the products being tested and hopes to have its testing completed by December
31, 1998. The products being tested for compliance include PASSPORT 5.1 release 
CAL215, PASSPORT 5.7 and PURE INTEGRATE (formerly Enterprise Integrator). Any 
releases newer than the above releases and any new products will also be Year 
2000 compliant. Customers on older generation products will be upgraded.

Based on the its assessments and current knowledge, the Company believes it will
not, as a result of the Year 2000 issue, experience any material disruptions in
internal processes, information processing or services from outside 
relationships. The Company believes that it will be able to manage its total 
Year 2000 transition without any material effect on the Company's results of 
operations or financial condition.

<PAGE>
 
PART II.  OTHER INFORMATION

ITEM 1.   LEGAL PROCEEDINGS

          The Company met with representatives of Case Associates, NV and
          Carleton Europe, NV on July 29 and 30, 1998 but was unable to reach
          any settlement agreement. The Company continues to vigorously defend
          itself against the claims made and to pursue its counterclaims. The
          Company filed a Petition for Descriptive Relief in Belgium and was
          able to seize the intellectual property being used by Carleton Europe
          after distribution rights were canceled by the Company. The litigation
          will continue in the United States and Europe with the discovery
          period set to begin in the near future. Costs incurred by the Company
          that relate to addressing any Carleton Europe issues can be offset
          against the notes payable to the former Carleton Corporation
          shareholders. See additional information contained in Form 10-Q for
          the quarter ended June 28, 1998.

ITEM 2.   CHANGES IN SECURITIES

          None.

ITEM 3.   DEFAULTS UPON SENIOR SECURITIES

          None.

ITEM 4.   SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
 
          Previously reported. See Form 10-Q for the quarter ended June 28,
          1998.

ITEM 5.   OTHER INFORMATION

          None.

ITEM 6.   EXHIBITS AND REPORTS ON FORM 8-K

          (a) Exhibit 99    Cautionary Statement

          (b) No reports on Form 8-K have been filed during this quarter.
<PAGE>
 
                                   SIGNATURES

Pursuant to the requirements of the Securities and Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                   CARLETON CORPORATION

Date:  November 10, 1998           By /s/ Steven Thimjon
                                      -------------------
                                      Steven Thimjon
                                      Vice President and Chief Financial Officer