Anaconda. Hmm, had I already? No idea. It is a Python installation that comes with a stack of scientific modules (NumPy, Matplotlib, PyLab and the like) and also delivers a number of useful modules. Plus IPython with the usual tools - so notebooks and QTConsole - and a command line tool for package management. The nice thing: the installation goes into its own path, so it does not necessarily affect another Python installation.