Apparently there is some sort of terrible virus that causes the PSP to turn into a "Windows box," a zombie-like amalgamation of badly written code, or a "Linux terminal," a violently dangerous Finnish virus that requires knowledge of something called a "command line" to extricate yourself from its clutches.
This virus requires something called a Bochs x86 emulator to prepare the PSP for impregnation by these evil virii. There are some shots of the virus in the wild and and explanation on how to reproduce the infection. Be warned.
Confirmed: Windows & Linux Run On The PSP [PSPUpdates]