cdrdao is a program for burning a CD-ROM in DAO (Disk At Once) mode. It also allows things like disk duplication and "cold runs" (test burning with laser off).
There are two "major" CD-burning command-line programs for Linux (and other *NIXes, as far as they've been ported), cdrecord and cdrdao, and cdrdao is the more powerful one because it allows much more flexible disk contents. For example, you can split up a single sound file across several tracks with no gaps between, or you can insert index markers to the track (some players show these and allow motion).
The flexibility has a price, though. You must make a disk description file for each burn effort, so cdrdao may not be for casual burning of data. However, some programs are able to generate the files on fly (for example, Linux VideoCD image mastering programs such as vcdimager generate both image and the track description file ready to be fed to cdrdao). The description format is documented on the manual page.
(Oh, and SCSI is not a requirement. I've used cdrdao many times successfully with an IDE drive, using the Linux kernel SCSI emulation.)