There are many ways that you can create assemblies. If you are one of the many programmers who prefer a command-line over point-and-click, you can simply open a command prompt and make use of the AL.EXE command-line utility. This is the Assembly Linker tool, and is used to link precompiled modules and resources into assemblies.
If you are creating a dynamic assembly, you will probably be using reflection to emit the assembly directly into memory. There are some situations in which this type of code is necessary, but it is by no means the most common way of creating assemblies.
Most developers will be creating assemblies with Visual Studio .NET (or another IDE if you don't use Visual Studio .NET). You create an assembly whenever ...