Wikipedia
Generative semantics is the name of a research program within linguistics, initiated by the work of various early students of Noam Chomsky: John R. Ross, Paul Postal, and later James McCawley. George Lakoff was also instrumental in developing and advocating the theory.
The approach developed out of transformational generative grammar in the mid-1960s, but stood largely apart from, and in opposition to, work by Noam Chomsky and his later students. This move led to a more abstract framework and lately to the abandonment of the notion of the CFG formal grammar induced deep structure.
A number of ideas from later work in generative semantics have been incorporated into cognitive linguistics, head-driven phrase structure grammar (HPSG), construction grammar, and into mainstream Chomskyan linguistics.