ucLinux and busybox should be discussed seperately. ucLinux is designed for machines that can't grok virtual memory. Since the x86 doesn't suffer from that problem, there is no need to use ucLinux. Furthermore, I believe that having a multi-threaded OS is more important then the resource savings, especially with the GUI requirements.
On the other hand, busybox, and to a certain extent uclibc are useful for the OLPC (in fact, the ROM image uses both). Unlinke ucLinux they don't limit us on full platforms like the x86, and they both work quite well with fully-leaded Linux. Mentioning them in the same breath as ucLinux does a disservice to them. --JordanCrouse (Talk to me!) 11:50, 21 August 2006 (EDT)
There's some misunderstanding here: uCLinux is essentially a set of kernel patches for systems without an MMU. Gumstix has a PXA processor, which has an MMU, and does not use uCLinux, they just use a normal kernel cross-compiled for ARM. uclibc is the C library for small systems (as opposed to using glibc). Gumstix uses uclibc along with busybox (lighter-weight user space).