… Isn’t master the current production code? How do you get a master that haven’t been touched in 15 years?

Ah yes, the ever growing and maintained X11 window system.

The future of security and standardization, with the mostly used feature of transmitting GUI assets over a network.

And to top it all off - the most documented code project, with the users facing easy customization options, that requires almost no programming language knowledge - and the easily compatible feature matrix, with allways up to date patch files.