Software Audio Console (SAC)
Software Audio Console is a pro audio product that emulates a full-blown digital mixing console on a Windows-based PC (along with other appropriate hardware). SAC isn't a toy; a fully-blown SAC system can cost anywhere from $2,000 to $25,000 (or more, if you really go crazy with high-end gear). However, the result is comparable to very expensive digital mixing system costing anywhere from $15,000 to $300,000. For the "anklebiter" or "weekend warrior" sound engineer, churches, clubs, and other venues, SAC provides a very cost-effective way to add a digital mixing console (with up to 72 stereo channels) to their sound system. SAC has been used on some National "A-name" tours (such as Telsa), major events, and other large shows.
You can find out more about SAC (and read all the promotional information concerning it) at http://www.softwareaudioconsole.com
You can ask questions about SAC at the SAC forum at http://sawstudiouser.com/forums/index.php
I own a small production company in Riverside, Ca. called Plantation Productions, Inc. In August of 2010, I purchased the SAC software and put together a 32-channel SAC system for use with the Riverside Festival of Lights and other gigs that Plantation Productions does. One problem with SAC from my point of view is that I'm not particularly enamoured with SAC's "mouse-based mixing" paradigm. Fortunately, SAC supports various hardware-based control surfaces such as the Mackie MCU and the Behringer BCF-2000. Unfortunately, I still wasn't happy with the level of control and the user interface, so I wrote some software of my own (in HLA assembly language, naturally) to interface a Behringer BCR-2000 (which is different from the BCF-2000) to SAC's "Wide Mixer" view. Now, combined with other control surfaces like the BCF-2000, I have almost complete physical control over SAC and rarely have to touch a mouse during a show.
The "SAC Control Surface" software I've written is free. You can download it here: SACCS
The documentation for SACCS can be found here: SACCS Doc
President, Plantation Productions, Inc.