When does the common language runtime terminate?
.net, c#, clr
Solution
The simple answer is: the CLR terminates when the host (process) terminates.
Also, there is a default AppDomain (that is not accessible). This AppDomain would continue to exist even if your AppDomain is unloaded. This is what I think Tigran was referring to as System.
Problem
There's a useful warning in the performance section on string interning on MSDN: the memory allocated for interned String objects is not likely be released until the common language runtime (CLR) terminates. But: when does the CLR terminate?