Spark ME is an AMAZING program. Particularly so, given that it is FREE.
We've already made a few recordings using our iMac and an iMic adapter, and the editing of sound files is dead-simple. There _could_ be a more comprehensive manual (you have to go to the company's website to download a PDF that gives a _little_ more info than the one that came with the download).
Still, for a simple two-track, wavelength-visible, cut-and-paste audio editor, SparkME is just faaaabulous!
ohenry, I'm far away from the iMac we use at the moment, so cannot check to see if I'm right in this, but I believe the file format is OMD, a universal file format for audio.
As for the question of Markers.... I haven't a clue, as that's not something I've had to do yet. I do know that during recording, SparkME seems to detect quiet spots and break up the recording into segments (audio detect?). In any case, you can cut/copy segments as standalone tracks, and create a playlist. That playlist is used when you click the "burn to CD" button, which launches Toast or whatever is the default CD burning utility on your system.