Software:

When operating two or more transmitters at one site, such as Outside  Broadcast ( ob ), In Ear Monitor ( iem ) for stage and studio use, or simplex / full duplex radio communications systems for talkback, then intermodulation products may developed in receiver front ends or transmitter output stages.  These appear as interference signals, and the use of frequencies where these occur should be avoided.

An extremely useful tool for calculating intermodulation products for such environments as multi-channel radio talkback or radio microphones has been designed and made available by TCS Consultants of Montgomery, Texas. 
You may also find the MPE (Maximum Permissible Exposure) calculations interesting as well.  All this information is here: www.tcstx.com

Another piece of software for calculating attenuator values, path losses etc., is released by RF Specialities Group, and may be downloaded from:  www.rfspec.com/rfs.htm