DesktopLyrics is an application that displays the lyrics of the song currently playing in "iTunes" right on your desktop. The lyrics for the song have to be set in iTunes; DesktopLyrics does nothing to fetch them if they aren't available in iTunes. If you don't want to set all your lyrics manually, you can use an application like "Harmonic".
In a nutshell, the Network Audio System (NAS) is the audio equivalent of an X display server. It was developed by NCD for playing, recording, and manipulating audio data over a network. Like the X Window System, it uses the client/server model to separate applications from the specific drivers that control audio input and output devices.
Festival is a general multi-lingual speech synthesis system developed at CSTR. It offers a full text to speech system with various APIs, as well an environment for development and research of speech synthesis techniques. It is written in C++ with a Scheme-based command interpreter for general control.
Minirok is a small music player for the K Desktop Environment. As its name hints, it's modelled after Amarok, but with a reduced set of features. In particular, it is designed to cover all the needs and wishes of the author, leaving everything else out. The look and feel is almost identical to Amarok's, though. The main interface is a tree view of the filesystem, with a playlist that can only be populated via drag and drop. There is no collection built from tags, so it's targeted at people whose collections are already structured in a tree at the filesystem level. Searches can be performed both in the tree view and the playlist.