If you are going to be format agnostic, the only one option is Kasenna MediaBase. It supports following formats: QuickTime, RealVideo, MPEG-1, MPEG-2 (!) and, possible, in future Windows Media. Server hardware may be driven by Linux or SGI IRIX.
Kasenna MediaBase is not free, but proven and stable.
If you are going to be format agnostic, the only one option is Kasenna MediaBase. It supports following formats: QuickTime, RealVideo, MPEG-1, MPEG-2 (!) and, possible, in future Windows Media. Server hardware may be driven by Linux or SGI IRIX. Kasenna MediaBase is not free, but proven and stable.