The Untold Origins of BSD: From Multics to Modern FreeBSD

FreeBSD is a free and open‑source Unix‑like operating system that has been under active development since 1993, but its origins actually predate Unix itself.

Before FreeBSD, there was Unix

The story of Unix began in the mid‑1960s with the Multics project, a collaboration among MIT, AT&T Bell Labs, and GE to build an experimental OS for the GE‑645 mainframe.

Multics introduced many concepts that later shaped modern operating systems, such as dynamic linking, hierarchical file systems, and memory‑mapped files, but its complexity led Bell Labs to abandon the project in 1969.

Undeterred, a small team pursued some of Multics' goals and created a new, smaller system that became Unix, developed at Bell Labs.

Notable engineers such as Dennis Ritchie, who later created the C language, and Ken Thompson, co‑inventor of the Go language, were part of this effort.

Unix was originally written in assembly language; the fourth edition in 1973 was rewritten in C, making it far more portable.

In 1975 the first source license was sold to the University of Illinois Computer Science Department, and Unix quickly spread throughout academia, giving rise to the so‑called “research Unix” variants.

Berkeley Unix Arrives

In 1974 Unix reached the University of California, Berkeley, where the BSD (Berkeley Software Distribution) system began to take shape. In 1975 Ken Thompson took a sabbatical, visited Berkeley as a visiting professor, installed Unix Version 6, and started experimenting with Pascal.

Students continued the work, creating an improved editor called ex . In 1977 a student, Bill Joy, compiled the first Berkeley distribution (1BSD), released on March 9 1978 with roughly 30 copies.

The subsequent 2BSD introduced tools still in use today, such as vi and csh, and saw about 75 copies distributed.

In 1978 Berkeley acquired a more powerful VAX machine, providing a new hardware target for BSD software. By 1979 the 3BSD release incorporated a new kernel that leveraged the VAX's virtual memory capabilities.

As BSD spread to more institutions and companies, users contributed patches and new programs, which were incorporated into later releases—an early open‑source movement that predated the term “open source”.

In 1989 the Net/1 release (Network Release 1) was published under the BSD license, featuring an OSI network stack implementation and new TCP/IP algorithms, motivated by rising AT&T licensing costs.

Keith Bostic then led a project to re‑implement the remaining AT&T utilities without using any AT&T code. The follow‑up Net/2 (1991) provided a nearly complete, freely distributable operating system.

In 1992 Bill and Lynne Jolitz released 386BSD 0.0, the first BSD version for Intel 386 hardware, bringing BSD to many home computers. Keith Bostic’s work was partly inspired by Richard Stallman, the father of the free‑software movement.

FreeBSD Begins

Later in 1992, 386BSD 0.1 laid the groundwork for both FreeBSD and NetBSD. A group of enthusiastic users collected bug fixes and enhancements, publishing unofficial patch sets. Disagreeing with the direction of 386BSD, they formed the FreeBSD Project in 1993 and began releasing their own distributions.

Thus, FreeBSD was born.