The Project: Bikesy is an innovative and open bike mapping system specially designed to find flat, safe, and fast bike routes anywhere in the SF Bay Area. The back-end and front-end code is completely open source on github. The underlying map data is from OpenStreetMap. Bikesy.com also has an API for developers to get bike routes easily into their own apps. More about Bikesyg entry. Walksy is optimized for mobile devices.
The Site: Bikesy.com