This Friday, April 6th, kicks off the beginning of the 14th annual anniversary bash for Epic Games' Jazz Jackrabbit 2. The anniversary bash is one of the biggest events of the JJ2 gaming year, and often features return visits from older players who haven't been active parts of the community in some years. The event will last for four days and will be hosted in two servers, one dedicated to CTF and one dedicated to Deathmatch/Battle, featuring in total ~30 of the best maps in each gamemode made in the past year or so.
The map packs aren't finalized yet, but I'll post links to download them once they are, so that you can preview the maps involved in advance or else put them in your cache to speed up downloading at the time of the bash itself. In the meantime, two servers (titled simply "Pre-bash battle" and "Pre-bash CTF") are cycling through some 300+ of the maps used in past bashes, likewise drawn from some of the best designers in the community. You can go directly to the servers using these links if you have the JJ2 URI Launcher installed. Otherwise, you can find them easily ingame by selecting New Game>Party Mode>Internet Play>Join Another Game (Client).
An out of the box install of JJ2 (using any non-shareware version) should be able to access and join the servers. If you have troubles with your connection timing out, you'll need to a) open ports 10052-10054 TCP and UDP and/or b) apply the fanmade patch JJ2+, which improves network connections, adds new multiplayer gamemodes, and fixes various bugs. I'm not sure I'm actually allowed to link to JJ2+ here, even though it's just a patch and doesn't include any of the original game files, but it's easy enough to find.