=== Atmel ===

 * AVR 8bit RISC microcontroller (ATmega 103L, ATmega 128, ATmega 64, and many others)

=== Motorola/Freescale ===

 * M68K family (including M68000, M68030, M68040 and M68060)

 * Coldfire 32bit CISC microcontroller (including MCF5272 and MCF5282)

 * 68HC705 8bit microcontroller family (several models)

 * DSP56K (DSP56805 and DSP56807E) - Used extensively for stepper motor control,
 data acquisition and other mechanical devices.

=== Intel ===

 * 80C196 - 16bit microcontroller;

 * 80x86 - Not properly a microcontroller, but used for some embedded Linux applications nevertheless.

=== ARM ===

 * Motorola Dragonball MX-1/MX-L - Helped porting kernel 2.6 to it. 

 * Intel PXA250/PXA255 - Wrote Linux kernel drivers for this chip

 * Atmel's AT91SAM7C3 - Small embedded application for the FreeRTOS real-time kernel.

 * (many others, evaluation only)


=== Texas Instruments ===

 * DSP TI54 series, employed for high-speed signal processing such as an FSK modem.


=== Zylog ===

 * Z80, mostly for experimental purposes.