History

The World of Warcraft guild Alea Iacta Est (AIE) was founded on February 13th, 2007, as a fan guild for several popular podcasts: The Instance, ExtraLife Radio, Buzz Out Loud, and Jawbone Radio. The guild grew rapidly, reaching the 500-member soft limit in its third week of existence. The soft cap didn't prevent new members from joining, but it did limit the number of online and offline members that were visible in the guild roster. The guild officers were able to manage the members using the command-line and a separate membership database despite never knowing exactly how many characters were actually in the roster.

On October 5th, 2010, a blue post by community manager Bashiok in the Public Test Realms (PTR) forum made the following announcement.

We will be introducing a new, hard cap of 600 members in a single guild for Cataclysm. This function will go live with patch 4.0.1 and is already live on the beta and PTR's.

As most of you already know, we have supported a soft cap of 500 members in a guild since World of Warcraft launched. We have allowed guilds to exceed the 500 limit up until now since being in a guild really just amounted to ranks and chat channels. With the advent of the new guild system in Cataclysm we are tracking many more things on each individual player in a guild and in order to support that, we need to limit the amount of members to a reasonable level.

The new cap of 600 members is fully supported in the new guild system and that means that everyone will be visible in the ui and able to contribute to all guild functions like experience and reputation gain. We have pulled a large number of statistics to get to the 600 member cap for guilds and we are happy to say that this value covers more than 99.9% of all the active guilds in World of Warcraft.

The small number of guilds that are over the 600 person cap will be able to keep their guilds intact (and fully supported in the new guild system), but they will not be able to add new members until they fall below the 600 member cap.

For AIE, which at the time had and estimated 3,300 members playing an estimated 6,600 characters, this was very distressing news. But AIE took it in stride, as was demonstrated by the comments of a member named Unwin in the guild forums.

it might seem sad, but our green wall doesn't have to come from Gchat. We still are a guild even if we are forced to split up into smaller guilds in game. We are not going anywhere, just the mechanics are changing.

AIE referred to guild chat as "the green wall" due to the default color of the guild chat in the WoW interface and the volume of traffic in guild chat.

Blizzard revised their initial announcement to set the new cap at 1,000 members. This didn't help extremely large guilds like AIE. Two representatives from other large guilds, Wasabe from The Spreading Taint and Mistiya from Goon Squad, contacted AIE and a meeting was arrange between the guilds. The group, calling themselves "Super-K", discussed various approaches to create something akin to the alliances of EVE Online.

At the time, the only add-on that had the type of functionality that was needed was Guild2Guild. This was used by The Spreading Taint, but it had significant drawbacks with regard to scalability and performance.

The Super-K group ultimately resulted in two cross-guild chat implementations: LemonKing's Cross Guild Chat and GreenWall. The implementations are very different, but they are designed for very different sets of requirements.

GreenWall development started on October 18, with alpha version 0.9.00 released on November 1. It was released on Curse on December 6.