ProtoFit is software for modeling the acid/base behavior of surfaces. The software is used for parameterizing surface protonation models and for visualization of potentiometric titration data.
IFEFFIT is a library and set of interactive programs for the analysis of x-ray absorption fine-structure (XAFS) data. IFEFFIT combines state-of-the-art analysis algorithms with graphical display of XAFS data, and general data manipulation. It can be
Molecular Graphics and Dynamics. Molecular model builder. Part of the Ascalaph Designer http://sourceforge.net/projects/asc-designer/ project. Windows & Linux.
A library of 3-D tools for vector algebra. Already in wide use for 3 decades in crystallographic applications.