Yes, this is exactly the problem. A lot of projects has closed source and would not gave them out. OK, they have there reasons...

But, a lot of projects did not see the need to port to the not so (for private persons common used) Unix platforms. About 5 % throughtput is done at SETI and SIMAP from non x86/x64 PCs with Windows or Linux or MacOS.
So there is also some good amount of work to port to other platforms. And a lot of projects did not have this resources...

If you search for some BOINC applications alternative platform support on x86/x75 on *BSD, you can also use the Linux Compat. I have written a short howto : http://www.dotsch.de/boinc/BSD_Linux-Compat_howto.html

For what OS+platforms do you excatly search binaries ?
At which projects are you interested ?

I tend to go with the *buntu distros because of the relative ease and my limited free time. As I get more time on my hands, I want to play around with each platform's "native" OS-- IRIX on the SGIs, AIX on the RS/6000s, Solaris on the Sun machines, etc. I am also trying to get a full microchannel IBM PC Server up and running with OS/2. If I only had more hours in the day!

You can see from my signature I run a lot of different projects.

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