Sega Europe has laid out plans to release a new hub for emulated Mega Drive games on Steam next week that includes a number of optional enhancements -- including support for game modding and mod-sharing via Steam Workshop.
People have been mucking around in the code of emulated games for decades, but it's still very rare to see a publisher make such a public show of embracing and encouraging modding of its old console games.
The details of how, exactly, Sega will permit people to mod these games is yet unclear, though a message on the Sega Europe Twitter feed today suggests the new Sega Mega Drive Classics Hub will be a "platform to share custom ROMs with other Steam users."
Sega has been publishing emulated versions of console games in its catalog to Steam for some time, and now has multiple packs of emulated Mega Drive games (or Genesis games, if you're in America) up on the storefront. When the new Sega Mega Drive Classics Hub debuts on Steam, anyone who already owns some or all of those Mega Drive games on Steam should see them automatically updated with mod support.
Gamasutra has reached out to Sega representatives for further details on this initiative, as well as whether or not it will be limited to Europe.