This points to a community-driven development model. The code was likely distributed among research groups, used, broken, fixed, and improved. The stability of v.2.21 suggests that it was a "canonical" version—a snapshot of code that the community trusted. It represents a moment where the software ceased to be a personal project for a single developer and became a shared tool.
The most prominent current application of is the January 2025 update for Cyberpunk 2077 ff2d v.2.21
This is strictly for retro enthusiasts . If you own the original disk card but your FDS drive belt is broken (a common issue), applying this v2.21 patch to your dumped ROM is the best way to preserve your gameplay experience without fixing the hardware. This points to a community-driven development model