OpenElectrophy – for multielectrode recordings

OpenElectrophy is a somewhat mature, actively developed, open source program for analyzing data from multielectrode recordings. It makes heavy use of Python and SQL and is developed by a team of French researchers including Samuel Garcia, Nicolas Fourcaud-Trocmé, Stéphane Gaétan Roux, and Christophe Pouzat.

It handles many file formats.

And has a rich set of tools for spike sorting.