The latest work will be on the dcip/dev branch:
https://github.com/simpeg/simpeg
A DC resistivity forward modelling and inversion package for SimPEG.
Documentation: http://simpeg-dc.readthedocs.org/en/latest/
Code: https://github.com/simpeg/simpegdc
Tests: https://travis-ci.org/simpeg/simpegdc
Bugs & Issues: https://github.com/simpeg/simpegdc/issues