GitHub for Mac has received its first major update, introducing a redesigned changes view that significantly improves the speed and ease of reviewing modifications. This update includes the addition of per-line committing to enhance the creation of meaningful commit messages by allowing users to select specific lines for commitment, paired with the new Commit & Sync feature that simplifies the sharing process to a single step. Other enhancements include support for Lion fullscreen, robust repository tracking even after renaming or relocation, and the app's ability to update itself automatically. The update, which involved 951 commits, also addresses bug fixes and performance improvements, marking a substantial advancement for GitHub for Mac users.