Installing backshift is a two step process:

1. Configure backshift (two examples, pick one of the two):
   • Use pypy - fast, and appears pretty much bugless in recent versions
     • ./configure --python /usr/local/pypy-1.8/bin/pypy
   • Use CPython - slowish, but can be sped up with Cython, and makes use of the reference implementation of Python
     • ./configure
2. Install
   • make install

After following those two steps, backshift should appear in /usr/local/bin.

You can also give "./configure a --prefix /usr" or similar, to change where backshift gets installed. By default, it goes under /usr/local.