Here is a list of independent Electronic Kit makers. I try to keep this updated often but its certainly not complete.

I don't consider these companies to be independent kit makers but I include them for completeness' sake

• Velleman
• CanaKit
• Elenco
• E-Kits

• PAiA Famous for their synthesizers, and other audio kits
• B.Y.O.C Build Your Own Clone, stomp boxes
• 4ms pedals kits of the guitar pedals described at CommonSound
• TonePad More guitar FX pedals
• Highly Liquid All sorts of MIDI and circuitbending kits
• Saratronics Makes a kit based off of a Philips SAA1099 sound generator
• AVI Showtech sells PCBs and kits for uCApps.de/MidiBox projects.
• Harrison Instruments More thememins than you can shake a stick at!
• Floppy Sponge MIDI/DMX kits mostly
• Hagerman Technology Audio kits
• Curious Inventor analog kits: Voice of Saturn, Sequencer, Modulator…
• Music from Outer Space analog modular synth kits

• 41Hz Audio amps
• HiViz Sound & Photogate triggers for electronic camera flashes (for "high speed" photography
• Critter Audio & Video synths
• Teuthis Open source MP3/audio players
• YAMPP MP3 players
• Techdesign EchoMP3 kit
• Engineers at Work have all sorts of MIDI kits

• TAPR sells all sort of kits for ham radio and other RF meddling
• Kazunori Miura Sells a $30 DDS adapter board kit based on the AD9833

• Alan Parekh Stair lighting kit
• Hypnocube LED Cubes
• Big Clive RGB Led kits
• Dropout Design LED 'Conways game of life' and disco dance floor kits
• Joule Theif Simple AA LED driver
• Joule Thief Low Voltage LED Driver

• Altairkit a complete reproduction of the 8800!
• Enigma-E Electronic Enigma (WWII cypher) machine kit
• replica 1 an Apple I reproduction

• Tux Graphics O.S. based microcontroller stuff
• Embedded Projects Shop sells a USB AVR programmer (Warning: you need a programmer in order to make this kit work, a real catch-22)

• Machine Science Educational robotics
• ROBOTMaker Micro & Nano Robot kits

• Frank Techniek Nixie/scope/binary clock kits and more.
• DutchTronix make a nifty little oscilloscope vector clock kit
• Tube Clock Makes some basic 4 & 6 nixie tube clock kits
• Denkimono Neat alarm clock kit that, well, just don't take it to the airport with you
• Share Brained Analog retro meter clock

• MadLab educational kits, some nice little things
• Evil Mad Scientist Some simple kits
• Japina Some kits in the store
• Mega Squirt DIY fuel injector computers
• Electroids Altoids-based kits
• Erlich Industrial Generic Kits
• Mignon Micro hand-held game kit
• ROBOTMaker 360 degree sensor kit