Hello again. I have another question. Is it possible to have Classic, OS X, Darwin and Linux on the same machine?. I would really like to make some comparisons among OS's to try to bring the best of them to Darwin. Particularly I'm concerned about: - Quality scheduling: Solaris has the most impressive scheduling system. Almost no load (except for "while(1) { fork(); }" executed without limits) can seriously affect its responsiveness. I would like to help bring such scheduling performance to Darwin. - I/O Performance: although things have improved dramatically, I think Darwin's I/O performance is not yet at best levels (CAUTION: I'm judging from OS X since I have not yet a Darwin copy, I may be wrong, it is up to you to prove me that), however I need to setup testing plans and tools, if you don't already have some. I would like to test I/O at the different arenas and draw conclusions. These arenas are basically network and disk I/O. USB and FireWire I/O seem to be fine, but testing and benchmarks should prove that too.