Cassandra is a 3D viewer and data analysis tools for 3d data set, based on VTK and Java (see:
http://www.artenum.com/FR/Produits-Cassandra.html) and JSynoptic is a 2D y=f(x) plotter (like Xmgrace) and based on JFreeChart (see:
http://jsynoptic.sourceforge.net/).
Ju.