KSEG is a program for exploring Euclidean geometry, similar to Geometer's Sketchpad. It features points, lines, transformations, measurements, calculations, simple editable recursive Constructions (similar to macros), adaptively sampled loci, and selection groups. Several languages are supported. KSEG is very fast, stable, and has an efficient and consistent UI. It uses Qt and does not require KDE.
KSEG 0.2 now has install routines If you had trouble building KSEG, try downloading again. Now the usual configure/make should work (assuming you have the necessary libs, of course).