Between 1989 and 1991, Rich worked at Commodore Business Machines with Amiga Unix. Between 1991 and 1995 he worked at Unix System Labs and from 1996 to 1998 with IP-level encryption at Sun Microsystems. He later left Sun and became one of the founders of the Open Directory Project. He stayed onboard until after the Netscape acquisition, and continued to work on the directory as well as Netscape Search, AOL Music and AOL Shopping. After his stint at AOL he went on to cofound Topix LLC, a Web 2.0 company in the news aggregation & forums market. In 2005, he and his fellow cofounders sold a 75% share of Topix to a newspaper consortium made up of Tribune, Gannett, and Knight Ridder.
Currently, he heads a new startup company, Blekko Inc, an internet search engine.
Skrenta was involved in the development of VMS Monster, an old MUD for VMS. VMS Monster was the inspiration for TinyMUD. He is also known for his role in developing TASS, an ancestor of tin, the popular threaded Usenet newsreader for Unix systems. In 1989 he started working on a multiplayer simulation game. In 1994 it was launched under the name Olympia as a pay-for-play game by Shadow Island Games.