For those of us outside of BTL, i.e. the Academic users, "Unix News" was created - which became ';login" - We started to meet informally at a few universities and talk to each other. Those of us on the ArpaNet that email/FTP and the like, started to share patches - but mostly things were shared when we got together via magtape. When they were held in NYC, we might be lucky and someone from Research might come (and even accidentally spill a few bits on the floor that mix fix something). Eventually, USENIX was formed, and we met twice a year formally. That was so popular, USENIX started having specialty conferences such as the one for C and C++, LISA, Networking, Linux and Free Software, etc. Similarly, with V7, UUCP was given to use a USENET was started by Tom Truscott and his famous "auto-dialler" that he hacked with a 12v relay, a DR-11C and described at the Bolder USENIX conference. Netnews was not far behind - which sadly became net.noise when the signal-to-noise ratio disappeared.
Yea, reading both the early usenix news letters and the early AUUG newsletters carefully shows more community action as well. I'm not sure what netnews was like in the 74-79 time frame before UUCP was wisely available, so I can't comment on that, but there's reports from names you'd recognize, and reports about USENIX conferences, reports about local gatherings... and then all kinds of crazy stuff: letters on university letter head that had bug fixes in it for this or that problem... Addresses where you write and send photocopies of AT&T and DEC licenses and get FORTRAN or MARCO-11 or other such things where people had used their DEC source license to hack in unix I/O routines into the FORTRAN compiler. And there were all kinds of 'user shared' programs that ranged from 'trivial problem, poorly executed' to 'really cool DEC OS emulators' depending on the era.. The bas.s that is in V6 and V7 (V5 too?) is an early version fo DEC's BASIC that was hacked for unix and some I/O devices that were specific to the labs... there were also advice for what versions of unix to use, and what versions were available to license. References to things that you can't google for anymore (or if you do all you find is the google index of the login issues / auus issues). There's also a number of country SIGs under DECUS that were for unix in the 77 or so time frame that might be good to search newsletters for... bitsavers has a bunch, but not sure they are early enough (I didn't come across the references to them until long after I looked at what bitsavers had).
The community aspect of open source was there in spades as well, with people helping other people and sharing fixes. But it was complicated by restrictive license agreements and somewhat (imho) overzealous protection of 'rights' at times that hampered things and would have echos in later open source licenses and attitudes that would develop in response. Even though the term 'open source' wasn't coined until 1998, the open source ethos were present in many of the early computer users groups, not least the unix ones. USENET amplified it, plus let in the unwashed masses who also had useful contributions (in addition to a lot of noise)... then things got really crowded with noise when AOL went live... And I'm sure there's a number of other BBS and/or compuserve communities I'm giving short-shrift here because I wasn't part of them in real time.
Warner