As someone who avoids reading the Forge, but nevertheless has been involved in discussion thereof, let me see what I can come up with.
The Forge is an internet forum dedicated to helping people publish their own, creator-controlled roleplaying games. It's been around a while, but achieved more prominence (AFAIK) when Ron Edwards took the helm.
Ron Edwards is, at the most basic, a dedicated RPG Theorist who firmly believes in what he's doing. He's written some exceedingly stupid turns of phrase, primarily centered around the concept that traditional RPGs are damaging to people's sense of story/concept of protagonism/actual physical brains (depending on who you believe), but he's a true believer in his cause one way or the other.
What's up with Forge Games? At the risk of sacrificing accuracy for brevity, they are games in which the old concepts of how an RPG works are, at the least, stepped back from and thought about; concepts like the sanctity of the character, the authority (and even existance) of the GM, the use of game mechanics as 'physics engine/world simulator', linearity of plot, etc. To some people, this represents what they want in a roleplaying game. To some other people, it represents interesting concepts to think about in their traditional gaming. To yet some other people, it represents so much sound and fury, signifying nothing. And to a small sub-set of people - you can probably think of a couple - it represents the gravest threat to their hobby that could be imagined, far exceeding B.A.D.D. and Jack Chick and FATAL-Con rolled into one. I mean, they wear the Viking Hat, goddamn it! Nothing else is right! Save vs. death magic!
Okay, that last bit was just for me, but the rest is my perception.