To learn about FreeBSD, first learn about BSD. This article introduces the brief history of BSD, and we can better understand FreeBSD by understanding the development history of BSD. BSD is the abbreviation of "Berkely Software Distribution" means "Berkeley Software Distribution". Obviously, the name of BSD is not what we now understand, and its original intent is not a simple operating system, but a collective software release. From the evolution of the software distribution to the operating system, it is important for FreeBSD. The BSD's appearance is traced back to the 1970s in the last century. When the University of California Berkeley, Bill Joy completed the "Berkely Software Distribution" merger in 1971 (including the Pascal system and an editor EX), even BSD The first release was born and about 30 free system copies were issued. The BSD user community has been expanding, in 1978, the software release has been updated and upgraded, and the results have generated the second edition of "Berkely Software Distribution", 2BSD, including enhanced Pascal, VI and Termcap. UNIX users must feel very intimate for VI and Termcap. 2BSD system copies are also free, and its last version 2.11BSD is still running in all corners of the world. The popularity of VAX computers has led to the birth of 3BSD at the end of 1979. 3BSD is the first VAX release version of Berkely, which is also JOY released, contains a large number of additional programs in C shell and 2BSD issues, and virtual memory kernel and standard 32 / v (the last Unix version of the Bell Lab, Run on the VAX) utility. In October 1980, Joy launched a new release version called 4BSD, including the Pascal compiler, Franz Lisp system, and mail processing system. 4BSD supports DARPA networks, copyright control is based on university, not based on single computer. In 1980, a team named CSRG (Computer System Research Group, Computer System Research Group) was set up to be responsible for the issuance of BSD, and released a new version called 4.1BSD in June 1981. Please note that not 5BSD. Since AT & T feels that 5BSD will confuse it and the AT & T UNIX SYSTEM V, Berkely agrees to change the name rules of the BSD future version, reserved the version number only on 4BSD, and only increase the small version of the latter number after 4. 4.2BSD was officially released in August 1983, and more than 1,000 sites licenses were issued in 18 months, which was very popular. In June 1986, 4.3BSD was released, and in 1988, CSRG released 4.3BSD-Tahoe, which is the first version of the BSD core decomposes to two parts: the machine and independent machine, this is very Value, it makes BSD to be transplanted into many different architectures. Since BSD uses some source code of AT & T UNIX, when the AT & T source code license fee is increasing, some want to use the BSD code to produce TCP / IP networked products to produce the AT & T code from the BSD release. Separate and issue a separate license terms without requiring the source code license of AT & T.
