z2pack is a package for computing Z2 invariants and other topological indices using the output of first-principles or tight-binding calculations.
The current version of the z2pack software is now hosted at ETH Zurich. The software may be downloaded from the main z2pack site, but there is also a web interface where you can run the program directly online.
If for some reason you need access to the original Version 0.1
of z2pack (now considered superceded),
see here.