SICSA is the Society for the Improvement of Conditions for Stray Animals. They take-in nearly 10,000 animals a year and find homes for nearly all of them. SICSA's mission is to reduce the stray pet population through spay/neuter programs, education, and placement. Euthenasia is only used when the animals health is failing or if its behavior is interfering with its adoption (if it's ferile, for example)
Right now SICSA is trying to raise funds for much needed additions to its building, so please check out their site and consider making a donation.