Eric Steven Raymond (born December 4, 1957), often referred to as ESR, is an American software developer, author of the widely cited 1997 essay and 1999 book The Cathedral and the Bazaar and other works, and open-source software advocate. He wrote a guidebook for the Roguelike game NetHack. In the 1990s, he edited and updated the Jargon File, currently in print as the The New Hacker's Dictionary.