Hi! I just want to let you know that MuTalk is available for Pharo-Dev versions 1.0 and 1.1 you can load it with monticello from http://www.squeaksource.com/MutationTesting MutationTesting-NicolasChillo.101 for loading last version in Pharo 1.1 (thanks to Francisco Ortiz Peñaloza) MutationTesting-GabrielBrunstein.97 for loading last verion in Pharo 1.0 More info here: http://code.google.com/p/mutalk/ We developed it with Nicolas Chillo for our career thesis but we will continue working on it. Basically, Mutation Testing is a technique for measuring and improving tests quality. All suggestions are welcome. Bests, Gabriel PS: it doesn't work with CogVM but I think that this problem will be solved with Pharo 1.2 (we must adapt it to work there).