Intracom system This is a full featured matrix system that runs on your PC or Mac (Boot Camp or Parallels).  Wireless First was the intercom supplier for a major corporate event which covered 5 cities and had 6 sites with 2 in New York.  Three global intercom chaqnnels were interfaced over the internet with astonishing audio clarity.  Watch a 60 second edited clip of Pete's screen during the event and hear the audio quality HERE. 
          Got a network in your company or production facility?  Add this (and a few DA/AD converters and relay control for other interfacing) and you have a matrix comm system.  Put a panel on every producer's laptop PC for inter show communication across the world.  Has normal internet latency issues, similar to cell phones, but for informational communication it's wonderful.  Point to point, party lines, Page, monitoring, telephone interfaces, GPIO, Port level volume control, automatic gain control on panel mic, radio interface...it's all there.  Who needs all that hardware!  (click on picture for a blowup-dimmed ports are not active and can be hidden)

Lectrosonics wireless Terrific selection of wireless equipment.  Check out the TM400 specifically designed for measurement microphones.  Look at the complete line.  The SM system is amazing too.  Use the RM remote to adjust the bodypack audibly THROUGH the mic while the pack is buried in the costume!

HME 2.5 GHz DX200 intercom system   This is an innovative wireless intercom system.  Aimed at the fast food market, it promises to be a useful tool in productions as well.  Automatic frequency allocation as well as dual channels makes it very easy and  convenient to use.  Because of the high frequency, it doesn't cover as well beyond the walls of your venue as analog RF intercom does, but additional antenna splitters are available to remote a second set of antennas.  Cut coax antennas can spread the usefulness over several rooms.

Norwest Productions This company is truly international.  Their ability to provide what amounts to "Local" service wherever they are sets them apart.  We have done several shows with them since the first at the Sydney Olympics and their personnel are the most friendly to work with.

Professional Wireless Intermod Analysis System In addition to a complete frequency analysis, the data for many RF products are self contained as well as direct FCC database download.  Enter a zip code and automatically bring up the TV stations in your area.  This is the most complete intermod program I have ever used.  Touring is very easy.  Just select the new TV station zone and click on recalculate all frequencies and you're done!  Free 15 day demo download

Media Numerics The final Audio over CAT5 solution.  Skip all the others.

Studio Technologies feature-rich, dependable professional audio products for studio recording, broadcast, film-post, and test applications.  Intercom announcers stations .  They make a terrific 2-4 wire converter with built in comm power supply to compete with and surpass the Clear-Com CCI-22. 
Check out the Model 46

Bright and Loud  Intermod program - terrifically quick and useful program to check your frequency lists for intermodulation problems.  Also a new forum to discuss audio related issues.

Hyperlink Technologies  Antenna systems for Wi-fi and 2.4 GHz HME DX200 systems

Clear-Com Intercom Systems  downloadable manuals (Most complete website of all manufacturers)

Wireless First - Terrific supplier of wireless microphones, in ear monitors, IFB and wireless intercom.  They also have a very extensive intercom equipment supply and some Riedel Digital Intercom systems.  Check out their web -- flashy and lots of information.

RIEDEL Communications  This has got to be the most amazing digital comm system ever.  The system also can distribute digital and analog audio, Ethernet and control for your entire show or facility.  Checkout the drawing in the downloads section from the Presidential debates.

ASL Intercom - Clear-Com compatible.  Interesting are dual, 4 and 6 channel biscuits with separate listen volumes, talk selectors and gooseneck mic.  International website too

Articles about intercom and FAQs from D. Richardson at Telex  Good general standards and practices for comm -  also good specific notes on several RTS products.

PL system theory, connector pin outs and black boxes for intercom  from Audio Specialties Group Amazing collection of information

Production Radio Rentals  Henry Cohen is a terrific source for communications RF and wireless control.

Intercom over IP Very interesting voice over Ethernet but not suitable for production use.  Con: Every station needs a computer. 

Everybody's Write - Screenwriters Initial Draft Pad: In this day of computers and the internet, here is a truly novel addition:  A pad of paper formatted to hand write, god forbid, those last minute screenplay additions.

Telex Intercoms  Manuals for most but not all of of their products.

Leon Audio talkback system  Interesting comm system!  Like a Clear-Com but with great signaling still only single channel comm though.

On Stage Audio was the audio supplier to the last Presidential debates.  They also have several Riedel digital intercom systems.

Jess Heimlich - Digital Communications Systems - Website of the busiest TV comms designer in the world.