Instant messaging was very popular in the latter portion of the nineties, and early to late aughts. Most of the prominent services then are gone now--MSN, AIM, and the earlier incarnations of ICQ, but there are a select people who have worked hard at reconstructing the crumbled buildings and preserving them. In this page, I'll show off some of them.
Website: Escargot Chat
Gitlab: Escargot / Escargot Server · GitLab
Arguably the most popular chat revival out there, frequenting 500-1000 users. Created by valtron in 2017 as an MSN 7 server, it's since gained support for versions through Windows Live Messenger 2009. The code itself is an open-source Python backend, though it's suffered some reliability and performance issues in recent times. Whether the project would regain activity since the rollout of WLM 2009 and Yahoo! Messenger support and subsequent server issues was uncertain, as former project lead walkingphasers was keeping the lights on in his spare time. In March 2021, Escargot's development and maintenance shifted hands to tonyshowoff, main dev of the NINA project, and Animadoria, an Escargot dev. Presently, he's aiming to attack some stability issues. Where the project will go from here is unknown, but my fingers are crossed.
I remember when I found Escargot not long after it came out on the MG forums. It was amazing to me that a more contemporary version of Messenger could work again, as someone who's never used it himself. Before Escargot, I had peaked in interest of an old Planet Source Code release called "Ashley's MSN Server" written in Visual Basic 6, that implemented MSNP4 and technically supported clients up to Messenger 4.6. I had fantasized about gathering the information to get it to support later versions of MSN, or if not that, get it up in a "production" environment. If I wouldn't, I hoped someone would. Then a guy came along not a year later with Escargot, and my dream of spamming people in group DMs was realized. Twas majestic.
Website: Home Page - OMessenger MSN Server
Pertinent forum thread: Made another MSN server - OMessenger Server - (messengergeek.com)
The other MSN revival created in late 2017, with a backend written in C# by jeffdev. Not open source to my knowledge, but versions up to 7.5 are supported.
GitHub: darcymiranda/PFire: Emulated XFire server (Client 1.127) (github.com)
Currently under early stages of development, PFire is an XFire server emulator written in C# with .NET 5.
Website: Phoenix - Chat Like It's 1999 (iwarg.ddns.net)
Phoenix is a service that aims to replicate the experience of AIM, ICQ, and Yahoo Messenger platforms.
It was notably covered by USA Today in 2018: AOL's instant messenger is back: Meet AIM Phoenix (usatoday.com).
Website: NINA (nina.bz)
NINA is a project maintained by tonyshowoff. It also hosts a forum and wiki for it and the Escargot project.
We're working to primarily rebuild the original AIM (AOL Instant Messenger), AOL (2.5 - 5.0+), and ICQ platforms as close to the originals as possible, and document the entire thing. We've made a lot of progress so far, we have all versions of AIM working up to version 8.0, and we have rudimentary AOL 4.0 and 5.0 support.
Progress has also been made as part of the project to bring back a little service called QuantumLink: the AOL's C64 predecessor.