Early Access? For a game that's been out since 2007? Yes, that is, in fact, a thing that can exist. Valve has decided to leave Mann Corp's doors ever-so-slightly ajar so that fans might run around on Team Fortress 2's magical murder playgrounds before they officially hit live servers. So it's a series of test servers for maps, essentially. Details below.
Valve explained its plans in a quick blog post:
"We need volunteers that are capable of putting these spaces through the wringer. We want to make sure they stand the test of time for future generations of mercenaries, so they may also enjoy the simple things in life, such as detonating explosive ordinance, setting men on fire and conga dancing."
"This is your chance to help guide the direction of TF2. You will get to participate in the development process as we cycle through different iterations of gameplay, based on your feedback."
As people play on them, maps will apparently change "a lot." Rule sets will likely change "drastically" as well. Despite that, players will be able to run beta maps on their own servers if they want.
So that's fun. A figurative peek inside the kitchen, if you will, only you get a nice meal instead of a series of profanities from a chef brandishing a worrisomely large knife.
To access beta maps, you need only select "play multiplayer" and then enable the "play beta maps" checkbox. Think you'll give it a go?