This is awesome program. I have been looking for something like this for long time. I can run it on my Mac and Windows using a USB (no need to install anything!). It is very fast for scientific computation (matrix calculations), compared to similar languages using Pythion. I do not mind to pay the membership fee (since its for lifetime)
SCaVis is an environment for numeric and symbolic computation. It is designed for data analysis, data visualization and any scientific computation. SCaVis can be used everywhere where an analysis of large numerical data volumes, data mining, statistical analysis and mathematics are essential (natural sciences, engineering, modeling and analysis of financial markets). SCaVis is fully multiplatform and runs on any platform where Java is installed. As a Java application, SCaVis takes the full advantage of multicore processors. The program has been under intensive development since 2005 and is currently very mature, with thousands of users around the world.