I love stumbling upon nuggets like this in Wikipedia:

Prior to the release, BSD’s implementation of TCP/IP had diverged considerably from BBN’s official implementation. After several months of testing, DARPA determined that the 4.2BSD version was superior and would remain in 4.3BSD. (See also History of the Internet.)

Here’s another:

Together with the Free Software Foundation and Linux, the CSRG laid the foundations of the contemporary open source community.