1 Exhibit 5.1 CHOATE, HALL & STEWART A PARTNERSHIP INCLUDING PROFESSIONAL CORPORATIONS EXCHANGE PLACE 53 STATE STREET BOSTON, MASSACHUSETTS 02109-2891 TELEPHONE (617)248-5000 FACSIMILE (617) 248-4000 TELEX 49615860 August 2, 1999 Ardent Software, Inc. 50 Washington Street Westboro, Massachusetts 01581 Ladies and Gentlemen: This opinion is delivered to you in connection with the registration statement on Form S-3 (the "Registration Statement") to be filed on or about August 2, 1999 by Ardent Software, Inc. (the "Company") under the Securities Act of 1933, as amended, for registration under said Act of 114,151 shares of common stock, $.01 par value (the "Common Stock"), of the Company. We are familiar with the Company's Certificate of Incorporation, as amended, its By-Laws, as amended, and the records of its corporate proceedings. We have also examined such other documents, records and certificates and made such further investigation as we have deemed necessary for the purposes of this opinion. Based upon and subject to the foregoing, we are of the opinion that the shares of Common Stock to be sold by the Selling Stockholders pursuant to the Registration Statement have been legally issued, fully paid and nonassessable. We understand that this opinion is to be used in connection with the Registration Statement and consent to the filing of this opinion as an exhibit to the Registration Statement. We further consent to the reference to this firm in the section entitled "Interests of Named Experts and Counsel" in the Registration Statement. Very truly yours, /s/ Choate, Hall & Stewart