The official Orbiter Forum is the largest forum in Orbiter.
List of Orbiter Forums
It is the original official forum but in February 2006, it was now completely error and transferred to another M6 forum.
It was the second part of the M6 forum since February 2008 due to old M6 forum error server. But sometimes down commonly from March to April 2008. As of April 14, 2008, it is now sometimes closed but still active on the Internet and archive only.
Old Meadville Space Center
In 2000, it was established by Rob Conley. But in 2005, it was transferred to another Meadville Space Center due to server errors. But as of April 10, 2008, it is partially active due to server errors.
New Meadville Space Center
Created in 2005 by Rob Conley due to server problems on the old one.
Created by SethEden. It is about Orbiter, Mars Direct, and Landsat.
Dan's Orbiter Forum
Created in 2003 by Daniel "DanSteph" Polli. It is still active and there are 2 languages available, English and French.
New M6 Forum
In February 2006, the old M6 forum is now in error and either never or can return. After the old M6 down, it has new forum that currently used today.
On March 19, 2008, the whole website around the world was down and already dead that can cause installation of M6.net.
On April 10, 2008, it has been recovered by Test 080410.
New Official Forum
As of April 2008, the new official forum is Orbiter-Forum.