Dynamic Aseembly

Normally, .NET assemblies (.exe or .dll) are built statically at compile time.

However, it's also possible to build them dynamically at run time using 'reflection emit' and the AssemblyBuilder class in particular.

It's a complicated subject but there's a 'simple' (well, relatlvely simple) example here on MSDN:

http://msdn.microsoft.com/en-us/library/system.reflection.emit.assemblybuilder(v=vs.110).aspx