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.