The GP2X? It runs Linux.
The GP2X is a South Korean handheld games console made by GamePark Holdings. It came out in 2005 - roughly a year after the Nintendo DS and the PSP, featuring roughly the same hardware capabilities. Two ARM cores - unusually, capable of overclocking - were supplemented by a whopping 64 MB of RAM, the display was roughly the same as the one on the DS, the battery life was decent - what's not to love?
This system was designed to be as open as possible. It featured virtually no first-party games, relying instead on the userbase to develop their own homebrew software. It became quite popular as an import in the mid-2000s, as it was an excellent machine for emulators. It could emulate virtually anything up to the original Playstation, albeit obviously it did some systems better than others.
As for the Linux system underneath it all, it was a fully featured OS hidden behind a custom UI. Hidden beneath was a version of Samba, a HTTP server, FTP and telnet. While the console itself didn't feature Wi-Fi, it could connect to the internet via USB networking.
Also notable is the expansion port. Users could use a multitude of special dongles to get composite television output, or to add USB ports to the console. Using a special breakout box, up to four devices could be plugged into the console at any one time.
And yeah, it also runs Doom.











