The Microsoft Security Development Lifecycle (SDL) is a program that aims to embed security practices into software development processes. It was created in response to the increasing threats targeting applications. By following the SDL process, which includes requirements, design, implementation, verification and release phases, Microsoft has seen measurable improvements in security, with vulnerabilities reduced by 45% for Windows Vista and 91% for SQL Server 2005 compared to previous versions. The SDL approach outlines best practices for application security and is available to help developers outside of Microsoft as well.