Windows users: msysgit is known to work. The app referenced in GitHub Bootcamp (link below) should work as well.
For OSX, see GitHub Bootcamp
For Linux, install git through your package manager.
Alternately (not recommended): download an archive of the latest code with no revision history by clicking here.
Linux users, install cmake via your package manager. For OSX and Windows, download from cmake.org
Lexer and parser?
v0.7 and later do not use flex or bison. Generated lexer/parser code is included. If changes to that code are necessary, you will need Baffled Citrus - perplex, lemon, and re2c.
Clone the repository
From the command prompt:
git clone git://github.com/stepcode/stepcode.git Git will create a
directory stepcode and clone the repository there. Once done, the
latest revision will be checked out. You will be able to view revision
logs, switch branches, etc - see Git