You mean a softsynth, yes there are plenty ranging from high end like Ableton (you can get a free trial) to cheaper stuff like Cubase. Although I'm sure there are probably free ones around if you search hard enough.
Example of Ableton being used to make almost a carbon copy of Smack my Bitch up
Last edited by mmoc5658f2333e; 2011-11-14 at 02:37 AM.
Reason: Added link
There's also Guitar Pro. But that's less mess around and more song writing. And the website Noteflight and... uhh... there's another program... starts with an S...