Cruising around the net, looking for the hottest in open source products, I stumbled upon this interesting tool: Linux MultiMedia Studio (or LMMS) is basically an FL Studio clone, which is open source and can be run on Linux or Windows.
I played around with the DAW briefly to see how it stacks up against FL Studio 7.
To begin, let's state that if you know your way around FL Studio, you won't find this a difficult GUI to master. You have all the same windows, more or less, like the piano roll, fx channel, sequencer, and browser window. The browser window is arguably more intuitive and better put together than in FLS.
I fairly quickly threw together a house beat loop out of the .ogg samples (a few one-shots) which come royalty-free with the program, and some cool VST plugs like the Tripple Oscillator (3xOsc anyone?).
But... the best part? You can use VST plugs with this DAW, so if you don't want to shell out $299 for FL Studio to use as a GUI with your VSTs, you may find this to be an interesting tool. Oh yeah, and did I mention? You can import .flp files.
It should be noted, however, that at this stage of develpment, LMMS lacks some visual finesse which so many FLS users enjoy. The windows do not stretch well, and the navigation is a bit cluttered/confusing to the untrained eye at first glance.
Through the LMMS site, there is a fairly comprehensive tutorial available on how to use the DAW.
LMMS allows you to render your completed projects as .wav or .ogg files, mp3 output is not currently available, unfortunately.
Long story short, if you are new to producing, have a limited budget but want something which has potential, or just want to try something new, check out LMMS.
Not sure on CPU usage, really didn't get a chance to try overloading my CPU, but I am on my laptop anyways. I have a feeling that this DAW probably is much less of a CPU hog, though, based on the simplicity of its design.
As the name suggests, I spent only about 5 minutes exploring this tool, so if you decide to try it out, be sure to post your own feedback here.