Apophenia: a library for scientific computing
►http://apophenia.info
Apophenia is an open statistical library for working with data sets and statistical models. It provides functions on the same level as those of the typical stats package (such as OLS, probit, or singular value decomposition) but gives the user more flexibility to be creative in model-building. The core functions are written in C, but experience has shown them to be easy to bind to in Python/Julia/Perl/Ruby/&c.
It is written to scale well, to comfortably work with gigabyte data sets, million-step simulations, or computationally-intensive agent-based models. If you have tried using other open source tools for computationally demanding work and found that those tools weren’t up to the task, then Apophenia is the library for you.