SAST stands for Static Application Security Testing. It's a method for analyzing source code, bytecode, or binaries to identify potential security vulnerabilities without actually executing the code. Think of it as a code review on steroids, but done by automated tools.  

Coverity is a popular commercial SAST tool. It's known for its ability to analyze large codebases and identify a wide range of vulnerabilities, including memory leaks, buffer overflows, and concurrency issues. Coverity is often used by large organizations to improve the security and quality of their software.