This is a quick heads up to all the Halo 3 fans who haven't already downloaded the add-on Heroic Map Pack. The three maps were released back in December for $10, but starting today, they'll be free for anyone to grab. It will certainly be nice to see them in much wider circulation. For those people who forget what three maps were included, here's a quick run down:
Standoff. Standoff is a big-ish symmetrical map—great for Team Slayer, excellentfor Objective games and big enough for a couple of vehicles. It haslocked-down Bunkers for bases and lots of cover for players trying tomake their way from one base to the next. Although some say it has asimilar feel to Blood Gulch, the geometry and terrain are very different.
Rat’s Nest. Rat's Nest is a massive level set in the corridors and tunnels of aHuman Base near Kilimanjaro. You may recognize parts of it from Halo3's Campaign mode. Effectively, it's a giant Oval, kind of like anunderground NASCAR track, with lots of vehicles and plenty of tunnelscriss-crossing the center area. It's designed for big team games,Objective and Slayer, but also works brilliantly for game types likeInfection and Territories.
Foundry. Foundry is a unique map designed from the outset to be the mostcustomizable Halo 3 Forge map ever created. It's a large Warehouse,which can be emptied quickly and then rebuilt any way you like, with abrand new palette of objects such as walls, ramps, Mancannons, and more.Stuff you never had access to before and objects that can be used tocreate fully functioning level designs, rather than simply altering ourexisting map.
The next bundle of content, the Legendary Map Pack, will be made available on April 18, again for $10. According to Bungie's update, there is currently no plan to release that pack for free, although hopefully in a few months it'll repeat the plan they had with the Heroic maps and open them up for everyone.

arstechnica.com