Agora dates back to 1985, when most "mere mortal" computers (those without access to the ARPANET, which was restricted to entities with a valid research justification and lots of money) connected with something called "UUCP" (Unix-to-Unix CoPy). Computers would call each other up periodically and exchange email and USENET messages. Many would make local calls amongst themselves, and one or a few local systems with deep pockets or Internet connections would carry the local traffic over the long distance links. In Portland, Tektronix was one of the major local "backbone" connections, to the tune of a $5000/month phone bill according to some rumors.
There were several of us in the late 80's: bucket, percival, agora (originally "skeeve", but changed due to a name conflict), qiclab, m2xenix, techbooks, probably others. I don't remember the exact dates, but I'm pretty sure percival was one of the first, though it varied as to its openness.
techbooks, which evolved into Teleport started in 86 or 87, I think. It started as a bookstore BBS, and then evolved into Unix. Jim suggested several times that we merge and go commercial, but with the Internet restrictions at the time, I didn't see it being practical, and also suspected that we'd have too many disagreements on how things ought to be run. So he found someone else, got big, and got bought out, while I'm still small potatoes. Such is life; I haven't regretted it too much.
Most of the others were open for a while, then closed up and became private, as I recall. agora is the only one that's still a locally owned public ISP, since Teleport has since been bought a few times over and is now part of Earthlink (as of 2002). The operator of m2xenix was one of the founders of RAINet, which was bought by Verio which is now part of NTT, though m2xenix itself was never a commercial operation. And, of course, there was a gold rush in the mid-to-late 90's and a number of ISPs started then are still around, such as Hevanet and Easystreet.
RAINet started in early 1991 as a loose collection of hobbyists interested in playing with SLIP (a simple-minded way of running TCP/IP over dialup connections). We set up some modem links around town and dreamed of Internet access one day, but back then you had to have lots of money and something vaguely researchish (i.e. wink in the right way) to get connected. In late 1991, Randy Bush (m2xenix's operator) had been, for some time, going to developing countries getting them electronically connected with uucp. m2xenix was something of a hub of international connectivity, I think. Because some of the software development we were doing to get ourselves connected also applied to the international efforts, we got a grant to get an Internet connection. Unfortunately, back then, Big ISPs could see an emerging market, and we were a Threat. The ISP of choice was Alternet, but they would only allow 5 sites to have access without paying for a separate connection, and each one had to have separate "research" justification. Unfortunately, I didn't wink the right way, so agora was behind a proxy for a while (1991/92 until 1993 when I finally got full access). Interestingly, Alternet stated publicly back then that proxies were a way around "redistribution prohibitions" and frowned on them.
While we were working out how to make a network work, we set up several computers in my basement and played with networking and routing. Since we were calling ourselves "RAINet", I decided this must be "RainDrop Laboratories", the research arm ;-) I liked the name so much, I made it my business name. Agora is the public access computer (hence the name) used by most customers of RainDrop Laboratories.
As a result of the inability for what was basically a coop to get ISP service, and with the relaxing of restrictions on Internet access, Randy and a couple of the others got some investment money and formed the commercial company RAINet for the primary purpose of selling IP connectivity without restrictions.
In 1994, I joined a new group at Intel investigating Internet technologies and setup Intel's first public web site. One of my co-workers saw the potential in what the combination of relaxing connections and Mosaic (the first graphical web browser, or at least the first one that caught on), and left Intel to start CityNet and paid for half of a T1 for agora in exchange for colocation, allowing agora to afford true high-speed access in late 1994. CityNet eventually became part of Excite.
Since then, the boom and bust have both become part of history, and things are where you see today...