Z-Maestro, from the people who brought you the Finestra virtual desktop utility, is a simple, easy-to-use, and promising digital audio workstation that offers multi-track audio and MIDI sequencing. It has some very nice features as well as some unique ones, but suffers too many rough edges. At this point the program remains very much a work in progress.
Just a couple of the rough spots I ran across were the lack of an indication when multiple notes were selected in the piano roll MIDI editor, and an error message when I tried to drag an audio file onto an audio track. I also found some of the icons unintuitive, and the Play button doesn't change to a Stop button when a file is playing (though it still functions as such).
Z-Maestro doesn't support VST FX or VSTi virtual instruments, but it does offer a few of its own FX and supports SoundFonts, which are a reasonable substitute for VSTis. Editing issimple, and the program feels very snappy compared to most DAWs. I hope the author will be able to maintain that sprightly feel as the program matures and gains more features.
Currently I can't recommend Z-Maestro as anything other than a quick and dirty recording app in its Lite incarnation. It has potential, but the demo version offers only three tracks and the pro version is far too immature to pay $30 for--especially when you can get powerful DAWs such as Cakewalk Music Creator or Magix Music Maker for only $20 more.
Note: The link takes you to the vendor's page, where you can download the software.