Sonos 4 is a software real time multiband FM processor for broadcasters. With a suitable sound card it is possible to turn a Windows PC into a broadcast limiter. The processor achieves its loudness through the use of a unique distortion masked final clipper (a distortion cancelled clipper). The sound quality and loudness is close to industry standard Optimods and Omnias.
More information. Screenshot.
Read the getting started page if you cannot get Sonos 4 working.
Sonos 4 is a free of charge application.
Maxx is a tool for final limiting or mastering of audio files in production environments. There is a manual interactive mode and a batch file processing mode using either a new two band (MBL2) processor or a nine band processor based on MBL9 from Sonos 4.
More information. Screenshots.
Read the getting started page if you cannot get Maxx working.