OtherOS was a feature in the Playstation 3, which was later discontinued and made unavailable throught a firmware update, that allowed one to install a custom operating system i.e. Unix or Linux like OSs. The reason for its discontinuation was perhaps the flexibility of  running OtherOSs and perhaps it challenged the reputation of their own OS.

Anyways, the Flavours that are known to have run on the PS3 are YellowDog Linux, Fedora, OpenSUSE and a versions of Ubuntu were actually ported to it too!