Don't click here unless you want to be banned.
The commons is the pool of backend server resources devoted to running LSL scripts, as well as public access to the skies of SL for travel and scripted objects--everything available to the general SL public that is not reserved for landowners.
The border between the commons and the private is the line where landowners rights cease. Specifically: landowners can specify "no outside scripts" up to 20 meters above the terrain of their land. Above that is common space for scripted objects. Landowners can return objects that are over their land... except TemporaryOnRez temp-on-rez objects--those are part of the commons. Also, the resources devoted to executing LSL scripts is all one big common pool--anyone can dip from the pool. In fact, landowners have to dip from the common pool in order to run their own scripts--there is no portion of LSL script resources that are reserved for them.
The only way to "withdraw" from the commons would be to buy a private island--owners of private islands have more control over their resources in that they have more control over who they allow access.
The commons are determined by the feature set of SL. This is key to the confusion about what is common and what is not--it is impossible for the commons to use up private resources--if the feature set allows you to use up some resource then it is common, by definition. Some people believe that a portion of the common resources are currently reserved for them--they are incorrect... sorta. Some resources should belong to them, but the feature set does not yet support it.
(Andrew Linden, 3/20/05
| Temporary On Rez