I'd like to introduce one of the more popular tools used for visualizing data within several scientific disciplines: ParaView. ParaView started as a joint project between Kitware, Inc., and Los Alamos National Laboratory back in 2000. The first public release was version 0.6, which came out in 2002. Since then, ParaView has become one of the most popular visualization packages for visualizing large data sets.

R is the de facto statistical package in the Open Source world. It's also quickly becoming the default data-analysis tool in many scientific disciplines. R's core design includes a central processing engine that runs your code, with a very simple interface to the outside world. This basic interface means it's been easy to build graphical interfaces that wrap the core portion of R, so lots of options exist that you can use as a GUI.