James Gordon Letwin (born July 2, 1952)[1] is an American software developer and one of the eleven early Microsoft employees who posed for an iconic staff portrait taken in Albuquerque in 1978.
[2] Prior to joining Microsoft, he worked for Heathkit, porting Colossal Cave Adventure to the computer[3] and working on HDOS and Benton Harbor BASIC.
Letwin contributed much of the design and code for several core components, including the HPFS file system.
[5] While at Microsoft he had become a millionaire, with a 2000 Time article estimating his worth at around $20 million.
[2] Since leaving Microsoft, Letwin has donated substantial amounts of money to environmental causes via the Wilburforce Foundation, a charitable foundation created by him and his wife, Rose.