Ralf Hotchkiss is an inventor and designer whose company, Whirlwind Wheelchair International, designs wheelchairs for use and manufacture in developing countries, involving wheelchair riders in all of its projects and activities. The organization's mission is "To make it possible for every person in the developing world who needs a wheelchair to obtain one that will lead to maximum personal independence and integration into society."  Himself a paraplegic, Hotchkiss is a 1969 graduate of Oberlin College
Hotchkiss published the design of his appropriate technology wheelchair along with a collection of information designed to guide the start of a small business to manufacture the design. The 1985 book, "Independence through Mobility: a Guide Through the Manufacture of the ATI-Hotchkiss Wheelchair," now available in PDF form through the Center for International Rehabilitation, is an early example of open design or open source hardware.
From his staff biography at Whirlwind:
- "Wheelchair-rider; engineer, inventor; Whirlwind co-founder; currently Whirlwind Chief Engineer and principal instructor in Whirlwind wheelchair design class; Women Pushing Forward (formerly Whirlwind Women) Advisory Board member; for 35+ years a wheelchair-designer - builder - trainer; 1989 MacArthur Foundation Fellow and recipient of countless other honors and awards; has worked in 42 countries teaching people who need wheelchairs how to build and maintain them for themselves." 
- About Whirlwind. Whirlwind Wheelchair International.
- Mr. Mobility: Wheelchair pioneer assembles global network of designers. San Francisco Chronicle, April 19, 1999.
- Meet the Fellows: Ralf David Hotchkiss. MacArthur Fellows Program, August 1, 1989.
- Ralf Hotchkiss. Independence through Mobility
- The Center for International Rehabilitation
- About Whirlwind staff. Whirlwind Wheelchair International.