IPython extensions allow custom magic commands to be shipped as standalone libraries. IPython includes a few extensions that define magic commands for working with code in other languages.
We are in the process of moving these builtin extensions to their parent projects (Cython, oct2py and rpy2). Once this happens this documentation will move as well.
Tutorials
Cython Magics: magics for compiling and running Cython code in a cell
Octave Magic: magics for running Octave code in a cell