jMathLab is a platform for mathematical and numerical computations. It uses the Matlab/Octave programming language. It runs on any platform where Java is installed, and can also run on the Web browser. The following packages are included: symbolic calculations (simplification, differentials, integration), numeric calculations, evaluations of mathematical functions, special functions, linear algebra with vectors and matrices, plotting data and functions, saving data (vectors and matrices) in files, random numbers, statistics, and solving linear and non-linear equations
FEDES is a Finite Element Data Exchange System for mapping finite element analysis data between different FE solvers and meshes with different element types and densities. Six commercial FE solvers are supported (ABAQUS, ANSYS, DEFORM, MARC, MORFEO, and VULCAN). The FEA data output can be visualized with ParaView.
MW is a low footprint embedded UI framework core intended for use on very limited systems. It embeds the JPEG, Freetype, and Cairo libraries, so it only depends on X. It should be fairly portable, as the only thing you need is to create a window on every platform and manage the events.