1. Cdrdao records audio CD-Rs in disk-at-once (DAO) mode, based on a textual description of the CD contents. Recording in DAO mode writes the complete disc (lead-in, one or more tracks, and lead-out) in a single step. DAO allows full control over the length and the contents of pre-gaps, the pause areas between tracks. From Redhat 8.0 RPM

2. Write audio or mixed mode CD-Rs in disk-at-once mode cdrdao creates audio or mixed mode CD-Rs in disk-at-once (DAO) mode driven by a description file. In DAO mode it is possible to create non standard track pre-gaps that have other lengths than 2 seconds and contain nonzero audio data. This is for example useful to divide live recordings into tracks where 2 second gaps would be irritating. It is also possible to create hidden tracks or track intros as found on commercial CDs. This tool can produce audio and mixed mode CDs. From Debian 3.0r0 APT

3. Writes audio CD-Rs in disc-at-once (DAO) mode allowing control over pre-gaps (length down to 0, nonzero audiodata) and sub-channel information like ISRC codes. Alldata that is written to the disc must be specified witha text file. Audio data may be in WAVE or raw format. From Mandrake 9.0 RPM