There's a mod for Halo Online that looks like it'll come pretty close to recreating the classic Halo experience on PC.
ElDewrito is a community-made mod for Halo Online, the cancelled free PC game based on Halo 3 Microsoft built for the Russian market.
ElDewrito lets you play multiplayer games in player-hosted servers, with multiple server browsers, player and emblem customisation, stat tracking and even ranked and social servers.
The mod launches in 0.6 form on 20th April, but to get an idea of the work that has gone into it, watch the video below. It's pretty impressive! The focus here is on the classic Halo gameplay created by Bungie, with dual wielding and equipment. Classic Halo 3 maps such as Valhalla and Guardian are present and correct, alongside brand new maps. There's a take on Forge mode, too.
The people behind ElDewrito stress it's not endorsed or affiliated in any way with Microsoft, Saber Interactive (developer of Halo Online), Bungie or current Halo custodian 343 Industries, but it's hard to imagine the lawyers at Microsoft will let this one slide, particularly if the company plans to release Halo 6 on PC as well as Xbox.
Until then, ElDewrito looks like a fantastic option for those who loved playing Halo: Combat Evolved back in the day on PC but fell out with the series after it went Xbox exclusive, or those who used to play Bungie's Halo games on Xbox and now fancy scratching that itch on PC. You can download it now from the ElDewrito website, or wait until Friday to play the latest version.