This page was prepared for a workshop at the Workshop on Modular Forms: Arithmetic and Computation, BIRS (Banff, Canada) 3-8 June 2007.
Magma has a huge amount of functionality for working with elliptic curves over Q, number fields, finite fields, and general fields.
It includes the database of all elliptic curves over Q with conductor less than 130000 (but none of the data in the database is made available apart from the curves themselves).
Pari/GP has a many functions for working with elliptic curves over Q, and a few fir general fields. There are also some add-on packages (e.g. mine for group structure over Fp and for analytic rank).
An optional extra database has all elliptic curves of conductor up to 130000, together with ranks and generators mod torsion.
Has all Pari/GP functionality and access to mwrank and my other elliptic curve programs, but currently there is a lot not yet available (unless you also have Magma installed)