Firefly Media Server (formerly mt-daapd) is an open-source media server (or daemon) for the Roku SoundBridge and iTunes. It serves media files using Roku Server Protocol (RSP) and Digital Audio Access Protocol (DAAP). The instructions for Firefly will involve compiling from the SVN version. This version has a somewhat better web interface than the lastest table release of mt-daapd and a few additional enhancements.
These instructions point to precompiled binaries for the PowerPC linkstations of the lastest stable release of mt-daapd (0.2.4)