Playing OGG files
The Nokia Internet Tablets don't have ogg support out of the box, but you can listen audio in this format by installing third party software. There is a feature request to have Ogg support in the tablets out of the box, see Bug #176: Support for OGG Vorbis / Theora missing.
Gstreamer ogg codecs
These codecs run on the main CPU, not on the DSP.
Ogg capable players if gstreamer ogg codecs are installed
- UKMP
- Kilikali
- Exaile port for maemo
- Kagu (uses osso-media-server like the built-in player)
- YouAmp
Players with built-in ogg capability
- Mplayer
- Vorbis Player (for the 770 only)
- mpd
See also this (long) InternetTabletTalk thread: gstreamer with ogg vorbis support
There is information for developers to enable ogg support in their applications at the "Getting started with multimedia" how-to pages for maemo 4.x, maemo 3.x, and maemo 2.2)