I have written a computer program called farsta for computing Gromov-Witten invariants of a complex projective manifold. If you provide a description of the cohomology ring of a manifold and supply a few Gromov-Witten invariants to get things started, then farsta tries to compute more Gromov-Witten invariants using associativity relations.
The program farsta is free to everyone. Click here to receive the program, which comes tar'red and gzip'ped. The current program version is version 1.1, dated 13 May 1997. You need a C compiler (prefarably GNU's C compiler) to build the program executable from the source code.
If you have any comments, questions, or suggestions, please send me e-mail.