EXHIBIT 5.1


October 24, 1997
Interleaf, Inc.
62 Fourth Avenue
Waltham, MA  02154

Gentlemen:

               I have assisted in the preparation of a Registration Statement 
on Form S-3 to be filed with the Securities and Exchange Commission (the 
"Registration Statement"), relating to 4,059,616 shares of Common Stock, $.01 
par value per share (the "Shares"), of Interleaf, Inc., a Massachusetts 
corporation (the "Company"), issuable to Lindner Growth Fund, a series of 
Lindner Investments and Lindner Dividend Fund, a series of Lindner 
Investments, pursuant to a certain agreement with the Company ("Agreement").

               I have examined (i) the Restated Articles of Organization and 
By-laws of the Company and all amendments thereto, (ii) the Agreement, and 
(iii) such records of meetings of the directors and stockholders of the 
Company, documents and other instrument as in my judgement are necessary or 
appropriate to enable me to render the opinion expressed below.

               In my examination of the foregoing documents, I have assumed 
the genuineness of all signatures and the authenticity of all documents 
submitted to me as originals, the conformity to original documents of all 
documents submitted to me as certified or photostatic copies, and the 
authenticity of the originals of such latter documents.

               Based upon the foregoing, I am of the opinion that the Shares 
have been duly authorized for issuance and, when issued your conversion of 
the Series C Convertible Preferred Stock in accordance with the terms thereof, 
will be legally issued, fully paid and nonassessable.

               I hereby consent to the use of my name in the Registration 
Statement and consent to the filing of this opinion with the Securities and 
Exchange Commission as an exhibit to the Registration Statement.

Very truly yours,


/s/ JOHN K. HYVNAR
- --------------------
John K. Hyvnar, Esq.
COUNSEL