<DOCUMENT>
<TYPE>EX-10.21
<SEQUENCE>35
<FILENAME>ex10-21_14663.txt
<DESCRIPTION>FORM OF SUBSCRIPTION AGREEMENT
<TEXT>
                                                                   EXHIBIT 10.21
                                                                   -------------

                             SUBSCRIPTION AGREEMENT


                                             Name of Subscriber ________________

Bridgeline Software, Inc.
10 Sixth Road
Woburn, MA 01801

Ladies and Gentlemen:

         1. SUBSCRIPTION. I (sometimes referred to herein as the "Investor")
hereby subscribe for and agree to purchase ___ Unit(s) (as defined below) of
Bridgeline Software, Inc., a Delaware corporation (the "Company"), on the terms
and conditions described herein and in the Private Placement Memorandum of the
Company and the Appendixes thereto (collectively, the "Offering Documents"),
each dated April ___, 2006, together with all supplements, if any, relating to
this offering. Terms not defined herein are as defined in the Offering
Documents. The purchase price per Unit is $100,000. The Minimum Offering is
$1,100,000, or 11 Units/the Maximum Offering is $2,300,000, or 23 Units. The
Units are being offered on behalf of the Company by registered broker-dealer
Joseph Gunnar & Co., LLC (the "Placement Agent"). The Company and the Placement
Agent have the option to increase the offering by up to an additional 5 Units,
or $500,000, on a "best efforts" basis. Affiliates of the Placement Agent and of
the Company may purchase securities in this Offering, and any such purchases
will be considered part of the Minimum Offering amount sold.

         THE AGGREGATE AMOUNT SUBSCRIBED FOR HEREBY IS $___________.

         THE UNDERSIGNED WILL PURCHASE THE FOREGOING UNITS FROM THE COMPANY ON
OR BEFORE THE TERMINATION OF THE OFFERING PERIOD (AS THE SAME MAY BE EXTENDED BY
THE COMPANY AND THE PLACEMENT AGENTS); IF AND ONLY IF THE COMPANY NOTIFIES THE
UNDERSIGNED THAT SUBSCRIPTION AGGREGATING $_______ HAVE BEEN RECEIVED AND
ACCEPTED BY THE COMPANY, AND REPRESENT GOOD FUNDS IN THE COMPANY'S ESCROW
ACCOUNT.

         2. DESCRIPTION OF UNITS; LOCK-UP. Each Unit consists of (i) an interest
bearing senior secured note in principal amount of $100,000 (the "Note"), and
(ii) a five-year warrant to purchase 10,000 shares of Company common stock, par
value $.001 per share ("Common Stock") at an exercise price of $.001 per share
(the "Warrant") (collectively, the Note and Warrant are referred to as a
"Unit"). The shares issuable upon exercise of the Warrant are eligible for
certain registration rights as set forth in the Warrant; provided, however, that
the Investor hereby agrees to certain six-month post-IPO lock-ups (as set forth
in the Offering Documents) pursuant to the underwriter's customary lock-up
agreement.

         3. PURCHASE; REGISTRATION RIGHTS.
<PAGE>

                  (a) I hereby tender to the Company cash or a check or wire
transfer (information to be provided to me on my request) made payable to the
order of U.S. Bank, AS ESCROW AGENT, as escrow agent for the Company in the
amount indicated above, an executed copy of this Subscription Agreement and an
executed copy of my Purchaser Investor Questionnaire. The wire information is:

         U.S. Bank
         ABA No.:  091000022
         Corporate Trust Services
         Acct. No.:  173103321050
         Attn:  Betty Hammer
         Ref:  Bridgeline Subscription Escrow, Acct No. 793506000

                  (b) The Offering shall terminate on the earliest of: (a) the
sale of the Maximum Offering, or (b) May 31, 2006, unless extended without
notice to the Investors by the Company and the Placement Agent for no more than
two (2) thirty (30) day periods (the "Termination Date"). Prior to the
Termination Date, payments delivered herewith will be held in an escrow account,
but may be immediately released to the Company upon acceptance of the
subscription. Upon the earlier of a closing for my subscription or completion of
the offering, I will be notified promptly by the Company as to whether my
subscription has been accepted by the Company.

                  (c) The Warrant and Warrant Shares shall have the Registration
Rights set forth in Section (j) of the Warrant.

         4. ACCEPTANCE OR REJECTION OF SUBSCRIPTION.

                  (a) I understand and agree that the Company reserves the right
to reject this subscription for the Units, in whole or in part, for any reason
and at any time prior to the Closing, notwithstanding prior receipt by me of
notice of acceptance of my subscription.

                  (b) In the event of the rejection of this subscription, my
subscription payment will be promptly returned to me without interest or
deduction and this Subscription Agreement shall have no force or effect. In the
event my subscription is accepted and the offering is completed, the funds
specified above shall be released to the Company.

         5. CLOSING. The closing ("Closing") of this offering may occur any time
and from time to time after the Company has received and accepted subscriptions
before the Termination Date. The Units subscribed for herein shall not be deemed
issued to or owned by me until one copy of this Subscription Agreement has been
executed by me and countersigned by the Company and the Closing with respect to
such Units has occurred.

         6. DISCLOSURE. Because this offering is limited to accredited investors
as defined in Section 2(15) of the Act, and Rule 501 promulgated thereunder, in
reliance upon the exemption contained in Section 4(2) of the Act and applicable
state securities laws, the Units are being sold without registration under the
Act. I acknowledge receipt of the Offering Documents and all

                                        2
<PAGE>

related documents and represent that I have carefully reviewed and understand
the Offering Documents and its exhibits. I have received all information and
materials regarding the Company that I have requested.

I fully understand that the Company has a limited financial and operating
history and that the Units are speculative investments which involve a high
degree of risk of the loss of my entire investment. I fully understand the
nature of the risks involved in purchasing the Units and I am qualified by my
knowledge and experience to evaluate investments of this type. I have carefully
considered the potential risks relating to the Company and purchase of its Units
and have, in particular, reviewed each of the risks set forth in the Offering
Documents. Both my advisors and I have had the opportunity to ask questions of
and receive answers from representatives of the Company or persons acting on its
behalf concerning the Company and the terms and conditions of a proposed
investment in the Company and my advisors and I have also had the opportunity to
obtain additional information necessary to verify the accuracy of information
furnished about the Company. Accordingly, I have independently evaluated the
risks of purchasing the Units.

         7. INVESTOR REPRESENTATIONS AND WARRANTIES. I acknowledge, represent
and warrant to, and agree with, the Company as follows:

                  (a) I am aware that my investment involves a high degree of
risk as disclosed in the Offering Documents and have read carefully the Offering
Documents.

                  (b) I acknowledge and am aware that there is no assurance as
to the future performance of the Company.

                  (c) I acknowledge that there may be certain adverse tax
consequences to me in connection with my purchase of Units, and the Company has
advised me to seek the advice of experts in such areas prior to making this
investment.

                  (d) I am purchasing the Units for my own account for
investment purposes and not with a view to or for sale in connection with the
distribution of the Units, the Notes, the Warrants, or the shares of Common
Stock issuable upon exercise of the Warrants, nor with any present intention of
selling or otherwise disposing of all or any part of the foregoing securities. I
agree that I must bear the entire economic risk of my investment for an
indefinite period of time because, among other reasons, the Units have not been
registered under the Act or under the securities laws of any state and,
therefore, cannot be resold, pledged, assigned or otherwise disposed of unless
they are subsequently registered under the Act and under applicable securities
laws of certain states or an exemption from such registration is available.
Furthermore, I hereby acknowledge and agree that I will not sell, transfer,
pledge, encumber, give or otherwise dispose of, either publicly or privately,
the Units, the Notes, or the shares of Common Stock issuable upon exercise of
the Warrants. I hereby authorize the Company to place a legend denoting the
restrictions on the Units that may be issued to me, as well as the Notes,
Warrants, and shares of Common Stock issuable upon exercise of the Warrants.

                  (e) Except as described in my Purchaser Investor
Questionnaire, I am not a member of the National Association of Securities
Dealers, Inc. ("NASD"); I am not and have

                                        3
<PAGE>

not, for a period of twelve (12) months prior to the date of this Subscription
Agreement, been affiliated or associated with any company, firm, or other entity
which is a member of the NASD; and I do not own any stock or other interest in
any member of the NASD (other than interests acquired in open market purchases).

                  (f) I recognize that the Units, as an investment, involve a
high degree of risk including, but not limited to, the risk of economic losses
from operations of the Company and the total loss of my investment. I believe
that the investment in the Units is suitable for me based upon my investment
objectives and financial needs, and I have adequate means for providing for my
current financial needs and contingencies and have no need for liquidity with
respect to my investment in the Company.

                  (g) I have been given access to full and complete information
regarding the Company and have utilized such access to my satisfaction for the
purpose of obtaining information in addition to, or verifying information
included in, the Offering Documents and related documents, and I have either met
with or been given reasonable opportunity to meet with officers of the Company
for the purpose of asking questions of, and receiving answers from, such
officers concerning the terms and conditions of the offering of the Units and
the business and operations of the Company and to obtain any additional
information, to the extent reasonably available.

                  (h) I have such knowledge and experience in financial and
business matters as to be capable of evaluating the merits and risks of an
investment in the Units and have obtained, in my judgment, sufficient
information from the Company to evaluate the merits and risks of an investment
in the Company. I have not utilized any person as my purchaser representative as
defined in Regulation D under the Act in connection with evaluating such merits
and risks.

                  (i) I have relied solely upon my own investigation in making a
decision to invest in the Company.

                  (j) I have received no representation or warranty from the
Company or any of its officers, directors, employees or agents in respect of my
investment in the Company and I have received no information (written or
otherwise) from them relating to the Company or its business other than as set
forth in the Offering Documents. I am not participating in the offer as a result
of or subsequent to: (i) any advertisement, article, notice or other
communication published in any newspaper, magazine or similar media or broadcast
over television or radio or (ii) any seminar or meeting whose attendees have
been invited by any general solicitation or general advertising.

                  (k) I have had full opportunity to ask questions and to
receive satisfactory answers concerning the offering and other matters
pertaining to my investment and all such questions have been answered to my full
satisfaction.

                  (l) I have been provided an opportunity to obtain any
additional information concerning the offering and the Company and all other
information to the extent the Company possesses such information or can acquire
it without unreasonable effort or expense.

                                        4
<PAGE>

                  (m) I am an "accredited investor" as defined in Section 2(15)
of the Act and in Rule 501 promulgated thereunder. I can bear the entire
economic risk of the investment in the Units for an indefinite period of time
and I am knowledgeable about and experienced in investments in the equity
securities of non-publicly traded companies, including early stage companies. I
am acquiring the Units for my own account for investment purposes only and not
with a view to the resale or distribution of such securities within the meaning
of the Act. I am not acting as an underwriter or a conduit for sale to the
public or to others of unregistered securities, directly or indirectly, on
behalf of the Company or any person with respect to such securities.

                  (n) I understand that (i) the Units and the underlying
securities have not been registered under the Act, or the securities laws of
certain states in reliance on specific exemptions from registration, (ii) no
securities administrator of any state or the federal government has recommended
or endorsed this offering or made any finding or determination relating to the
fairness of an investment in the Company and (iii) the Company is relying on my
representations and agreements for the purpose of determining whether this
transaction meets the requirements of the exemptions afforded by the Act and
certain state securities laws.

                  (o) I understand that (i) since neither the offer nor sale of
the Units has been registered under the Act or the securities laws of any state,
the Units may not be sold, assigned, pledged or otherwise disposed of unless
they are so registered or an exemption from such registration is available, and
(ii) it is not anticipated that there will be any market for the resale of the
Units.

                  (p) I have been urged to seek independent advice from my
professional advisors relating to the suitability of an investment in the
Company in view of my overall financial needs and with respect to the legal and
tax implications of such investment.

                  (q) If the Investor is a corporation, company, trust, employee
benefit plan, individual retirement account, Keogh Plan, or other tax-exempt
entity, it is authorized and qualified to become an Investor in the Company and
the person signing this Subscription Agreement on behalf of such entity has been
duly authorized by such entity to do so.

                  (r) The information contained in my Purchaser Investor
Questionnaire, as well as any information which I have furnished to the Company
with respect to my financial position and business experience, is correct and
complete as of the date of this Subscription Agreement and, if there should be
any material change in such information prior to the Closing of the offering, I
will furnish such revised or corrected information to the Company.

         I hereby acknowledge and am aware that except for any rescission rights
that may be provided under applicable laws, I am not entitled to cancel,
terminate or revoke this subscription, and any agreements made in connection
herewith shall survive my death or disability.

         8. INDEMNIFICATION. I hereby agree to indemnify and hold harmless the
Company and its officers, directors, stockholders, employees, agents, and
counsel against any and all

                                        5
<PAGE>
losses, claims, demands, liabilities, and expenses (including reasonable legal
or other expenses, including reasonable attorneys' fees) incurred by each such
person in connection with defending or investigating any such claims or
liabilities, whether or not resulting in any liability to such person, to which
any such indemnified party may become subject under the Act, under any other
statute, at common law or otherwise, insofar as such losses, claims, demands,
liabilities and expenses (a) arise out of or are based upon any untrue statement
or alleged untrue statement of a material fact made by me and contained in this
Subscription Agreement or my Purchaser Investor Questionnaire, or (b) arise out
of or are based upon any breach by me of any representation, warranty, or
agreement made by me contained herein or therein.

         9. SEVERABILITY. In the event any parts of this Subscription Agreement
are found to be void, the remaining provisions of this Subscription Agreement
shall nevertheless be binding with the same effect as though the void parts were
deleted.

         10. CHOICE OF LAW AND JURISDICTION. This Subscription Agreement shall
be governed by and construed in all respects under the laws of the State of New
York, without reference to its conflict of laws rules or principles. Any suit,
action, proceeding or litigation arising out of or relating to this Agreement
shall be brought and prosecuted only in federal and state courts in the City,
County and State of New York. The parties hereby irrevocably and unconditionally
consent to the jurisdiction of each such court or courts located within the
State of New York and to service of process by registered or certified mail,
return receipt requested, or by any other manner provided by applicable law, and
hereby irrevocably and unconditionally waive any right to claim that any suit,
action, proceeding or litigation so commenced has been commenced in an
inconvenient forum.

         11. COUNTERPARTS. This Subscription Agreement may be executed in one or
more counterparts, each of which shall be deemed an original but all of which
together shall constitute one and the same instrument. The execution of this
Subscription Agreement may be by actual or facsimile signature.

         12. BENEFIT. This Subscription Agreement shall be binding upon and
inure to the benefit of the parties hereto.

         13. NOTICES AND ADDRESSES. All notices, offers, acceptance and any
other acts under this Subscription Agreement (except payment) shall be in
writing, and shall be sufficiently given if delivered to the addresses in
person, by Federal Express or similar courier delivery or by facsimile delivery,
as follows:

                  Investor:           At the address designated on the signature
                                      page of this Subscription Agreement.

                  The Company:        Bridgeline Software, Inc.
                                      10 Sixth Road
                                      Woburn, MA 01801
                                      Attn: Thomas Massie, President and CEO
                                      Fax: (781) 376-5033

                                        6
<PAGE>

                  With a copy to:     Morse, Barnes-Brown & Pendleton, P.C.
                                      Reservoir Place, 1601 Trapelo Road
                                      Waltham, MA 02451
                                      Fax: (781) 622-5933
                                      Attention: Joseph C. Marrow, Esq.

         or to such other address as any of them, by notice to the others may
designate from time to time. The transmission confirmation receipt from the
sender's facsimile machine shall be conclusive evidence of successful facsimile
delivery. Time shall be counted to, or from, as the case may be, the delivery in
person or by mailing.

         14. ENTIRE AGREEMENT. This Subscription Agreement constitutes the
entire agreement between the parties with respect to the subject matter hereof
and supersedes all prior oral and written agreements between the parties hereto
with respect to the subject matter hereof. This Subscription Agreement may not
be changed, waived, discharged, or terminated orally but, rather, only by a
statement in writing signed by the party or parties against which enforcement or
the change, waiver, discharge or termination is sought.

         15. SECTION HEADINGS. Section headings herein have been inserted for
reference only and shall not be deemed to limit or otherwise affect, in any
matter, or be deemed to interpret in whole or in part, any of the terms or
provisions of this Subscription Agreement.

         16. SURVIVAL OF REPRESENTATIONS, WARRANTIES AND AGREEMENTS. The
representations, warranties and agreements contained herein shall survive the
delivery of, and the payment for, the Units.

         17. ACCEPTANCE OF SUBSCRIPTION. The Company may accept this
Subscription Agreement at any time for all or any portion of the Units
subscribed for by executing a copy hereof as provided and notifying me within a
reasonable time thereafter.

RESIDENTS OF ALL STATES: THE UNITS OFFERED HEREBY HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED, OR THE SECURITIES LAWS OF ANY STATE OR
OTHER JURISDICTION AND ARE BEING OFFERED AND SOLD IN RELIANCE ON EXEMPTIONS FROM
THE REGISTRATION REQUIREMENTS OF SAID ACT AND SUCH LAWS. THE UNITS ARE SUBJECT
TO REGISTRATIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR
RESOLD EXCEPT AS PERMITTED UNDER SAID ACT AND SUCH LAWS PURSUANT TO REGISTRATION
OR EXEMPTION THEREFROM. INVESTORS SHOULD BE AWARE THAT THEY WILL BE REQUIRED TO
BEAR THE FINANCIAL RISKS OF THIS INVESTMENT FOR AN INDEFINITE PERIOD OF TIME.
THE UNITS HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND EXCHANGE
COMMISSION, ANY STATE SECURITIES COMMISSION OR OTHER REGULATORY AUTHORITY, NOR
HAVE ANY OF THE FOREGOING AUTHORITIES PASSED UPON OR ENDORSED THE MERITS OF THIS
OFFERING OR THE ACCURACY

                                        7
<PAGE>

OR ADEQUACY OF THE OFFERING DOCUMENTS. ANY REPRESENTATION TO THE CONTRARY IS
UNLAWFUL.


































                                        8
<PAGE>

Manner in Which Title is to be Held. (check one)

___ Individual Ownership
___ Community Property
___ Joint Tenant with Right of Survivorship (both parties must sign)
___ Partnership
___ Tenants in common
___ Corporation
___ Trust
___ IRA or Keough
___ Other (please indicate)

                                           Dated:
                                                  ------------------------------

INDIVIDUAL INVESTORS                       ENTITY INVESTORS
                                           Name of entity, if any
---------------------------------
Signature (Individual)
                                           By:
                                               --------------------------------
                                                *Signature
                                           Its
---------------------------------               --------------------------------
Signature (Joint)                               Title
(all record holders must sign)                        --------------------------


---------------------------------          -------------------------------------
Name(s) Typed or Printed                   Name Typed or Printed

Address to Which Correspondence            Address to Which Correspondence
Should be Directed                         Should be Directed

---------------------------------          -------------------------------------

---------------------------------          -------------------------------------
City, State and Zip Code                   City, State and Zip Code

---------------------------------          -------------------------------------
Tax Identification or                      Tax Identification or
Social Security Number                     Social Security Number

          * IF UNITS ARE BEING SUBSCRIBED FOR BY ANY ENTITY, THE CERTIFICATE OF
          SIGNATORY ON THE NEXT PAGE MUST ALSO BE COMPLETED

The foregoing subscription is accepted and the Company hereby agrees to be bound
by its terms.

                                           BRIDGELINE SOFTWARE, INC.

Dated:                                     By:
       --------------------------              ---------------------------------
                                               Thomas Massie, President and CEO



<PAGE>

                            CERTIFICATE OF SIGNATORY


        (To be completed if Units are being subscribed for by an entity)



         I, _______________________________, the _______________________________
                 (NAME OF SIGNATORY)                         (TITLE)

                  of______________________________ "Entity"),               a


                  ________________________________________
                               (NAME OF ENTITY)


                  ________________________________________
                               (TYPE OF ENTITY)


hereby certify that I am empowered and duly authorized by the Entity to execute
the Subscription Agreement and to purchase the Units, and certify further that
the Subscription Agreement has been duly and validly executed on behalf of the
Entity and constitutes a legal and binding obligation of the Entity.

         IN WITNESS WHEREOF, I have set my hand this       day of        , 2006.



                                                       -------------------------
                                                              (SIGNATURE)






<PAGE>

                                   SCHEDULE A


Anderson, Neil T.
Auersperg, Paul
Balfour Associates LP
Burg Family Trust
Callahan, Brian
Coldrick, William
Davenport, Edward C.
Davis, James
Dupree, Thomas
Fortune Footwear
Freed, Albert
Herbert Wrabel Living Trust
High Capital Funding, LLC
Jia, Charles
Kotler, Elia
Landy, John
Lefebvre, Scott & Suzanne
Lowrance, Larry
Massie, Thomas & Theresa
McCoy, Robert S.
Panagolpolous, John & Betty
Rizos, George
Troutman, John
Baker, Christopher P.
Davis, James
Dupree, Thomas
Heffernan, Ronald
Kersch, Mitchell & Allison
McLemore, Robert
Mead, Ian D.
Seeger, Robert & Kara
</TEXT>
</DOCUMENT>
