Sharing a free VST sound font player and a resource for downloading hundreds of free instruments. These programs can be used with any program (FL, Protools, Logic, etc) but the installation instructions are specifically for ACID Pro.
How to install vsts: http://www.youtube.com/watch?v=mEsvyobxyh0
Download SFZ for free: http://www.cakewalk.com/support/project5/sfz.aspx
Download free soundfonts: http://themusictip.com/producers-corner/
More free loops and samples: