The Wine project isn't the only free software project with official releases being few and far between, but the Haiku Project is in a similar boat. Development on Haiku, the open-source reincarnation of BeOS, started back in 2001 but the first alpha release was only released last year. This month, however, the second alpha release of the Haiku OS has arrived...
It would be interesting to see some basic benchmarks (IO, disk r/w, GLXgears..) of HaikuOS vs. Linux in Phoronix articles. It definately feels like snappiest system around, but feeling isn't worth knowledge.
GL benchmarks would be pointless its sofware rendering still... gallium and native drivers may or may not be in progress (there was a guy working on a linux driver layer but it may not be releaasable since he did it at his workplace)
And of course Haiku already has a gallium port which is worked on occasionally (search aljen in the bug tracker)
IO benchmarks would be relevant .. compile times and transcoding audio etc would as well.
BTW you can boot up haiku with as little as 48Mb ram now but it only becomes usable around 96Mb which is enough to load the Web+ browser and open facebook.com. Them min recommended is of course still 128Mb ram....
In the past, I downloaded the VMWare image of the previous alpha of Haiku in order to see if I can port an application I'm maintaining to this OS. After I was unable to install the needed development tools because of lack of disk space (45MB free :-/). So I gave it up.
I was hoping that the alpha 2 will address the problem of free disk space. But to my astonishment, it didn't. I can't possibly imagine why anyone would limit the size of the first virtual HD this way. It's impossible to install this: