USENET newsgroups were some of the first online communities. Before the web, there was USENET, and there were communities for (what seemed like) every subject under the sun. There was nothing called "spam", many groups were carefully moderated by humans to insure no "flame wars" broke out and nothing off-topic got posted. It was the best time of the Internet, IMO.
My first experience on the Internet wasn't the World Wide Web - it was USENET. Specifically, it was soc.org.nonprofit.
The soc.org.nonprofit USENET newsgroup was created on 27 June 1994 and bidirectionally gatewayed to the email mailing list usnonprofit-l@rain.org (USNONPROFIT-L). It was set up for the discussion of nonprofit management and program issues. It was founded by Michael Chui, then of Indiana University. The gateway between the newsgroup and email group was operated for many years as a public service by RAIN.ORG of Santa Barbara, California. The archives are available via GoogleGroups.
Some of the people who volunteered their spare time outside of their full-time jobs to post regularly to soc.org.nonprofit in 1994 and 1995 were:
Here are the soc.org.nonprofit Frequently Asked Questions (FAQs) and their answers, as of 1996: