The OWASP Comprehensive, Lightweight Application Security Process (CLASP) is an "Activity driven, role-based set of process components whose core contains formalized best practices for building security into your existing or new-start software development life cycles in a structured, repeatable, and measurable way"
In other words, it is one method of many (others examples are Microsoft SDL and Software Security Touchpoints) for implementing a secure development process.
A couple months ago, I created a presentation that gave a high-level overview of CLASP. I wanted to make this presentation available to the community as well as gather input from industry practitioners regarding how feasible this model is within their environment. I encourage anyone who is interested to join the OWASP CLASP mailing list or comment directly.
The presentation can be found here: OWASP CLASP Overview