Except when the author of the project says he won't roll Win32 support into mainline development. Then it's the only option, but it's an option available solely because the author open-sourced his code under a license that allows it. Which is awesome.
> Client libraries will have to spend time making sure they
> comply with both versions
I'm not sure that's the case. If I'm writing a Redis library (say Resque), I'm going to ensure it works with Redis. If it's also usable on Windows because of redis-win32, awesome, but that's not something I'd go out of my way to ensure.
> development in general will slow as each project will have fewer total
> devs.
What? Why? Why would a project have fewer devs? Are you assuming some developers will work only on redis-win32 and not on mainline Redis? I don't think that follows -- changes to mainline Redis will probably be merged downstream into the win32 fork by that fork's maintainers, who wouldn't otherwise be working on Redis.
