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EXHIBIT 5.1
July 26, 2000
Mainspring, Inc.
One Main Street
Cambridge, MA 02142
RE: Registration Statement on Form S-1
Pursuant to Rule 462(b) Relating to 575,000 shares of Common Stock
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Ladies and Gentlemen:
This opinion relates to an aggregate of 575,000 shares of common stock, par
value $.01 per share ("common stock"), of Mainspring, Inc. (the "Company"),
which are the subject matter of a Registration Statement on Form S-1 filed with
the Securities and Exchange Commission (the "Commission") pursuant to Rule
462(b) under the Securities Act of 1933, as amended, on July 26, 2000 (the
"Registration Statement").
The 575,000 shares of common stock covered by the Registration Statement
consist of 500,000 shares being sold by the Company, and 75,000 shares subject
to an over-allotment option granted by the Company to the underwriters (the
"Underwriters") named in the prospectus (the "Prospectus") incorporated by
reference in the Registration Statement.
Based upon such investigation as we have deemed necessary, we are of the
opinion that when the 575,000 shares of common stock to be sold by the Company
pursuant to the Prospectus have been issued and paid for in accordance with the
terms described in the Prospectus, such shares of common stock will have been
validly issued and will be fully paid and nonassessable.
We hereby consent to the filing of this opinion as Exhibit 5.1 to the
Registration Statement and to the reference to our firm in the Prospectus under
the caption "Legal Matters."
Very truly yours,
/s/ Testa, Hurwitz & Thibeault, LLP
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TESTA, HURWITZ & THIBEAULT, LLP
