Veteran Microsoft engineer Raymond Chen has dropped another nugget of Microspeak - the "fun fork."

While forking a repository nowadays can be anything other than fun - just ask HashiCorp about OpenTofu - in Microsoft parlance of old, a "fun fork" is a code branch that will never get merged back into the parent, one where engineers can try out their wild and wacky ideas without fear of their code somehow turning up in production.

Chen explained: "The idea of the fun fork is that it will never be merged back to the parent branch. Do whatever you want! Nobody will care!"

According to Chen: "The term 'fork' comes from an old internal Microsoft source control system that did not support branches, so the only option was to fork the entire code base."

That old source control system was likely nothing to do with Microsoft's Visual Sourcesafe, which was known for causing the odd four-letter word also beginning with "F" to be uttered by engineers.

Chen added: "Usually, a fun fork is created so that a team can experiment with a large, complex feature. If the experiment proves successful, the team can move the changes from the fun fork to a product branch."

While Windows might be where fun goes to die, at least for the poor admins tasked with deploying it, it's good to know that the Microsoft gang can - or at least used to be able to - grab the source for some uncontrolled tinkering and general fun times.

The resulting code might never see the light of day unless the experiment was a success, in which case it would likely need some refactoring at the least or rewriting from scratch at worst.

Chen explained: "The actual code in the fun fork is not usually taken verbatim directly into the product. It will probably be cleaned up, say by removing things that didn't pan out, removing dead code, refactoring for maintainability."

Sadly, Chen did not reveal the Microsoft projects that started out as a fun fork, so The Reg has fired up the speculation machine.

Recall is an easy target and, we suspect, might still be a fun fork with horrified engineers realizing that before they had a chance to rewrite it, it was seized by managers desperate to show something to justify all those AI investments.

Or then there is the ill-fated Windows 8 user interface, which, on the desktop at least, was a fork that was anything but fun. ®

https://www.theregister.com//2024/06/27/microsoft_windows_fun_fork/