Walnut Creek CDROM (Walnut Creek, California) was an early provider of freeware, shareware and free software on CD-ROMs. The company was founded in August 1991 by Bob Bruce and was one of the first commercial distributors of free software on CD-ROMs. The company produced hundreds of titles on CD-ROMS, and ran the busiest FTP site on the Internet, ftp.cdrom.com, for many years.

In the early years, some of the most popular products were Simtel shareware for MS-DOS, CICA Shareware for Microsoft Windows (now the WinSite archives), Slackware Linux, and FreeBSD. As more users gained access to high speed Internet access, demand for software on physical media decreased dramatically. Walnut Creek also gained fame for its idgames directory, which was the de facto distribution center for the Doom-engine modification community at the time.

The company merged with Berkeley Software Design (BSDI) in 2000 in order to focus more engineering effort on the similar BSD Unix operating systems FreeBSD and BSD/OS. The software assets of BSDI were acquired by Wind River Systems in 2001, and the FreeBSD unit was divested as a separate entity, again led by Bob Bruce, in 2002 as FreeBSD Mall, Inc.http://www.freebsdmall.com/  Slackware Linux was spun off as the Slackware Linux Store.http://store.slackware.com/

Walnut Creek CDROM's URL, www.cdrom.com, is now redirected to Simtel.net.