Download Porting Kit
There are two version of the Porting Kit: Porting Kit and Porting Kit Legacy. Porting Kit is compatible with macOS 10.8 and above, has the Screen Recording feature and uses a more recent version of Sparkle, which grants safe updates. In the meanwhile, Porting Kit Legacy is compatible with macOS 10.6 and above.
In case you have macOS 10.8+, download Porting Kit. In case you don't, download Porting Kit Legacy instead.