It's not just software, you need mic's and a device to interpret it. The easiest way fix a room for most of us is with something like the Audyssey system found in many newer receivers and as a stand alone unit. Andrew Robinson AVRev's managing editor reviewed it here;
The Meridian 861 v4 does room correction as well and will print waterfall plots for your room showing you where the problem frequencies are, but to my knowledge this is the only unit that does this.
Some subwoofers such as the Revel's come with a calibration disc that you can use to find the 'hot' frequencies in your room, but you have to go through them all and test each with a SPL meter. Not to difficult, but it can become tedious.