The article claim that an MMU and minimum bit width of 32-bit is required for Linux. Wasn't µCLinux rolled back into the official kernel, meaning that with the right configuration the Linux kernel will run on CPUs without an MMU and with bit widths less than 32-bit? Eg. the H8 [1].

Perhaps the author meant to write "Ubuntu", rather than "Linux"?

[1] http://kernel.org/doc/readme/arch-h8300-README