OGRE is rendering engines and one of open source projects which I always watch. It has many users' favors, good toolkits and detail documents. When I began watching OGRE, it had not released regular version yet. So users had to check out source code and compile it to watch the progress of OGRE project in every times. OGRE had been at 0.9.x for a long time, and official team and 3rd party developed various toolkits in the meantime. I thought OGRE might not be completed because the plan of OGRE is too large. But, OGRE had been released as regular version with many toolkits and official documents.
OGRE has given much effects to other projects, and some projects about OGRE started. CEGUI is the best project of them. OGRE, CEGUI and some toolkits bring easy 3D programing to hobby or other category. For example, we can see OGRE applications in SIGGRAPH. These libraries are useful to test our opinion. Also students in a certain Germn game school use OGRE to learn 3D programing.
But, OGRE isn't popular in Asia. That reason is that users in Asia can't use their mother language in OGRE because it doesn't support UTF-8. Some solutions have been suggested, and there is also 3rd patch. But there is no official solution. This thing might continue to be hot topic in OGRE for a while.