http://pexarithmeticsolver.codeplex.com/

FloPSy is a SBST extension designed for handling floating-point constraint solving in Microsoft Pex unit testing tool. It was developed by Kiran Lakhotia and is avaliable for freely as an open-source project.

http://code.google.com/p/moretest/

MORETest is a multi-objective test suite minimisation tool written in Python. It was developed by Shin Yoo at University College London and Robert Nilsson at Google Switzerland. The tool internally uses Two-Archive multi-objective evolutionary algorithm developed at University of Birmingham. The tool is availably freely as a open-source project.

http://code.google.com/p/austin-sbst/

AUSTIN is an open-source structural test data generation tool (for unit tests) for the C language, developed by Dr. Kiran Lakohtia at University College London. It is designed as a research prototype and the aim of this project is to aid researchers in automated test data generation using search-based algorithms. It is based on the CIL framework and currently supports a random search, as well as a simple hill climber that is augmented with a set of constraint solving rules for pointer type inputs.