Guillaume Maillard of the BlueEyed OS is talking to TotallyBe. He speaks of the differences between their project and OBOS and Cosmoe. He also claims that when programmed for and/or patched the right way, the Linux kernel and XFree can be very fast and perform pretty adequately to BeOS 5 (UI responsiveness – the main advantage of the BeOS experience), while in most of the “other” cases, Linux is much faster than BeOS 5 (eg. server operations, compilation times, SMP scaling, VM etc). I have personally talked to Guillaume and also tested some of his BlueEyedOS code recently and indeed, XFree can be fast, when you know how to directly program for it (without using layers and layers of other libraries that is). No matter the tricks and optimizations though, XFree/Linux kernel can’t be as responsive as BeOS at the end of the day, because of the way the BeOS was built around the push programming model and extreme multi-threading (‘fast’ is not the same as ‘responsive’ – BeOS’s UI is extremely responsive, but the OS *underneath* is not ‘fast’ on many-many cases). These vast differences in architecture between BeOS and the other traditional OSes, made BeOS a heaven for the user but a nightmare for the developer whose applications involve more than one window or might be a bit complex.