William Stein, number theorist at University of Washington, founded and built up Sage. It's designed to be cloud-based and acts as a common interface for many t

William Stein, number theorist at University of Washington, founded and built up Sage. It's designed to be cloud-based and acts as a common interface for many things (including Mathematica, Maple, Matlab, etc.) but also has it's own libraries. Will recently went on leave from UW to work full time on Sage. Description from: http://www.sagemath.org/ http://www.sagemath.org/ "SageMath is a free open-source mathematics software system licensed under the GPL. It builds on top of many existing open-source packages: NumPy, SciPy, matplotlib, Sympy, Maxima, GAP, FLINT, R and many more. Access their combined power through a common, Python-based language or directly via interfaces or wrappers. Mission: Creating a viable free open source alternative to Magma, Maple, Mathematica and Matlab."