A pre-packaged Debian file system is available. The instructions of installing in the FLASH memory on the board is here,
http://glomation.net/smf/index.php/topic,8.0.html. The instructions on how to install on a USB drive can be found here,
http://glomation.net/smf/index.php/topic,146.0.html. The usual Debian package management tools can be used to install software packages.