rOpenSci creates technical infrastructure in the form of carefully vetted, staff- and community-contributed R software tools that lower barriers to working with scientific data sources on the web. rOpenSci also creates social infrastructure through a welcoming and diverse community, and promotes advocacy for a culture of data sharing and reusable software.
The Astropy Project provides software tools and infrastructure to facilitate research by professional astronomers. In addition to maintaining a core Python package, the Astropy Project supports the development of high-grade affiliated packages by members of the astronomical community.
SymPy is a library for symbolic mathematics, which means performing mathematical calculations exactly (as opposed to inexact numeric calculations from libraries such as NumPy).
The Shogun Machine Learning Toolbox is devoted to making machine learning tools available for free, to everyone. It provides efficient implementation of all standard ML algorithms.
Julia is a fast and user-friendly programming language for high-performance scientific computing.