Some examples are shown below.
Link to the Castles & Crusades sale page
Astral Virtual TableTop is the easiest way to create, host, and play tabletop roleplaying games. Astral has partnered with DriveThruRPG to launch a new experience that makes running tabletop roleplaying games immersive, simple, and fun for both Game Masters and players. Use Astral to play with friends online, or as a helpful tool around the gaming table. Play any tabletop roleplaying system in Astral by importing and sharing your favorite titles purchased through any DriveThru site, including DriveThruRPG and Dungeon Master's Guild.
All accounts come with a ready-made starter template, tokens, audio files, and a helpful guide to help you get started. Use Astral for free, or level up to a Pro plan to unlock automation tools and 10,000 assets (designed by Mythic Portal Games) that come with every Pro account.
Fantasy Grounds just released officially licensed AD&D 2E modules for the PHB, MM, DMG and N1 adventure.
We added a 2E ruleset to all Standard and Ultimate licenses where people can enter their own data if they don't want to buy the preloaded module content we sell.
There is a free extension that makes the 2e ruleset a AD&D ruleset.
You actually get the rules engine (automation) free with the program. You need to buy the books to get the content, but you could enter is all yourself if you wanted to.
DCC also got an official ruleset the same day.