The Wiard Synthesizer Company designs and manufactures the 300-series (Proproetary 6U format) and 1200-series (3U frac-rack compatible) lines of synthesizer modules.
Grant Richter builds the Wiard series of modules. His older, discontinued, 300 Series is highly collectible (in 6U format.) Current 1200 Series modules are built by Grant himself. They are based on the "Frac-rack" system, require plus or minus 15v power and are calibrated 1v/octave. Connections are 1/8" mini-jacks. Currently available modules include a joystick, the Joystick Axis Generator, Noise Ring, and the Borg and Boogie Filters. (excerpted from Doug Wellington's excellent Analog Notes site).
Wiard's webpage can be found here: http://www.wiard.com
Several Wiard designs have been licensed for production by other manufacturers:
Additionally, the "Wogglebug #3" design has been left available to the public by Wiard, and heavily embraced by the Synth DIY community