On proxus, we have so called versions. These versions aren't with a set date, usually a new version gets released when a large part of the community thinks it's time for a world reset. Often these new versions are accompanied with a new minecraft release. After a new release, the old version often gets retired in a few weeks, with a world download to be found on the maps download page
Version 3 (v3)
This version runs on 1.13, we introduced real economy, and introduced a datapack. Also the discord got a little overhaul, focussing more on the community. Also the name got changed from "Proxusmc" to simply "Proxus"
Version 2.2 (v2.2)
This is a world reset of version 2.1, with almost no plugins and running 1.13 preview versions. This version was created because players were getting a little bored; and we wanted to test out 1.13 things, this world isn't a "real" version, this is why it only got a minor version bump.
Version 2.1 (v2.1)
This is a refresh of version 2, with all new plugins etcetera. The world didn't get reset here, because players weren't feeling ready yet. It was mostly created due to some major plugin issues with v2.0, that only the world wasn't changed.
Version 2.0 (v2)
This version doesn't have a world download, because the world got transfered to v2.1, This was the continuation after V1, introducing a new spawn and a custom world generator.
Version 1 (v1)
This version is the first one after the name change to ProxusMC, This introduced an diamond based economy system, voting and a lot more modern systems. It was released at October 1 2017, 18:00 UTC
Season 5 (s5)
This is the contuniation after the Season 4 server, Back then the server was called "Unofficial Hermitcraft Fan Server", this name was later changed to "Proxus" After the hermitcraft owner didn't feel like this was a thing we were allowed to do. This one also featured a creative server, to test out redstone things and buildings. At the end of this version, issues with the staff team creating their own server (that ultimately closed, as it wasn't open to the public and didn't sustain it's costs) is got shut down early.
Season 4 (s4)
This is the first real version of Hermitcraft fans server, but back then it was called "HermitFanServer". Basically this was the first one with real public drawn to it, still hosted out of the owner's home :). It was very much based on hermitcraft and didn't have any economy, just claiming and block logging. This is basically where Proxus started as a minecraft server. This server was still whitelisted, with an online application process that allowed access to the server. It was a pretty closed, but still fun community. Also this is the first season where donations were possible. This server had quite a lot of players at it's peak times, but not a lot of new players joining at all.
Season 4 Beta (s4-beta)
This was one of the first servers we created, It didn't really suceed that well. I (Xeyame) still wasn't experienced with hosting back then, There wasn't a website or anything. Just an ip address shared over things like youtube comments. This was pretty much based on trusting each other, as it didn't have any block logging plugins. Sadly only the world download of this server is still stored, the other files have dissapeared. This is when I started with servers, and it's still part of proxus these days. This is estimated to be started around mid 2016, and ran for about 190 days.