Theo de Raadt is the eldest of four children to a Dutch father and a South African mother, with two sisters and a brother. Concern over the mandatory two-year armed forces conscription in South Africa led the family to emigrate to Calgary, Alberta, Canada in November 1977. In 1983, the largest recession in Canada since the Great Depression sent the family to the Yukon. Prior to the move, De Raadt got his first computer, a Commodore VIC-20, which was soon followed by an Amiga. It is with these computers that he first began to develop software.
The NetBSD project was founded in 1993 by Chris Demetriou, Adam Glass, Charles Hannum, and De Raadt, who collectively felt frustration at the speed and quality of Jolix, the standard Berkeley software distribution then, and believed that a more open development model would be of greater benefit to development of an operating system. Jolix, also known as 386BSD, was derived from the original University of California Berkeley's 4.3BSD release, while the new NetBSD project would merge relevant code from the Networking/2 and 386BSD releases. The new project would center its focus on clean, portable, correct code with the goal being to produce a unified, multi-platform, production-quality, BSD-based operating system.
Because of the importance of networks such as the Internet in the distributed, collaborative nature of its development, De Raadt suggested the name "NetBSD", which the three other founders agreed upon.
The first NetBSD source code repository was established on March 21, 1993 and the initial release, NetBSD 0.8, was made in April 1993. This was derived from 386BSD 0.1 plus the version 0.2.2 unofficial patchkit, with several programs from the Net/2 release missing from 386BSD re-integrated, and various other improvements. In August 1993, NetBSD 0.9 was released, which contained many enhancements and bug fixes. This was still a PC-platform-only release, although by this time work was underway to add support for other architectures.