Like most grassroots movements, there’s no specific date when this got started. It’s tough even to say whether what we’re seeing is a true renaissance or just greater visibility thanks to the web. Old-school blogs are easy to find. I run across a “new” one every couple of days. The best of them are outstanding. They offer some of the best RPG blogging out there.
Every edition has its adherents who never jumped to a newer version; they get everything they want from whichever generation of D&D they’re playing. What distinguishes the OSR from people who never stepped away from AD&D or OD&D is the appearance of retroclone games. Retroclones are newly written games that emulate the rules and frequently the writing style of D&D rules from the 1970s and early ’80s. These publications are made possible by the OGL and the SRD (and possibly by a lack of interest or time in the Wizards of the Coast legal department).
(Read the rest at Kobold Quarterly ...)