In BubbaJunk.com, Inc. v. Momentum Software, Inc., No. 03-03-00590-CV, 2004 WL 904081 (Tex. App.--Austin Apr. 29, 2004, pet. denied), BubbaJunk and Momentum entered into a written consulting contract in which Momentum promised to perform software- and Internet-development services described in two work authorizations attached to and incorporated into the contract. Id. The contract required that changes to the scope of the services be in writing and executed by both parties. Id. When BubbaJunk failed to make payments under the contract, Momentum sued for breach of contract and eventually moved for summary judgment on its claim. BubbaJunk asserted promissory estoppel as an affirmative defense, alleging that Momentum made additional promises regarding the scope of its services in an unsigned software requirements specification. The court held that because the software requirements specification was not executed by both parties, it was not a part of the contract and would not support BubbaJunk's promissory estoppel defense.