Assemblies and Namespace

Question

Does everything in a single namespace compile into its own assembly?

Answer 1

Assemblies and namespaces have nothing to do with each other except that there's a generally used convention that the full names of classes in an assembly will match the assembly name (in some way).

It's strictly a naming convention - as Guffa said, assemblies can define classes for more than one namespace and the classes that exist in a namespace can come from more than one assembly.