Gecode is an attempt to construct an open, free, portable, accessible, and efficient environment for developing constraint-based systems and applications.

gecode is radically open for programming: it can be easily interfaced to other systems. it supports the programming of new propagators (as implementation of constraints), branching strategies, and search engines. new variable domains can be programmed at the same level of efficiency as finite domain and integer set variables that come predefined with gecode.