It's a python repl, it has a bunch of useful syntax extensions such as autocall(not needing to type parens after no args calls and around one arg calls) ? ?? for help summary, syntax higlighting, readline, tab completion, optional integration with GTK, Qt or wxWidgets toolkits(ie letting you build and interact with guis in repl).
ipython has a client/server model with multiple gui frontends including a qt one that lets you print out inline graphs and ipython notebook which lets you generate documents with code and data analysis/visualization. I believe the last part is what the grant is for.
Python has been used in scientific and statistical fields a lot lately and ipython notebook is quite useful for that.
It is now much, much more than that. Besides the notebook (that allows you to mix python, images, math, etc... inside an html browser: http://ipython.org/ipython-doc/stable/_static/notebook_specg...), you get a powerful engine capable of distributing computation between different machines.
