E-Cell System is an object-oriented software suite for modelling, simulation, and analysis of large scale complex systems such as biological cells. It allows many components, driven by multiple algorithms with different timescales, to coexist. The core library is written in C++ with a Python binding, and frontend software uses Python.
PyTraffic is a Python version of the board game Rush Hour created by Binary Arts Coporation. The goal is to remove the red car out of the grid through the slot on the right. To do this you have to slide the other cars out of the way. PyTraffic comes with about 19,000 puzzles ranging from intermediate to expert, and has an extremely smart hint facility which is able to find the best move in every position.
STklos is a free Scheme System conforming to R5RS. The implementation is based on an ad-hoc Virtual Machine. It can also be compiled as a library, so that one can easily embed it in an application. Its features include an efficient and powerful object system based on CLOS, a simple-to-use module system, implementation of the full tower of numbers defined in R5RS, and easy connection to the GTK+ toolkit. STklos is the successor of STk, a Scheme interpreter tightly connected to the Tk toolkit.