My short summary

This comparison is mainly originated with attention to XML-based configuration possibilities and grouping implementations of the same contract which are choosable over a key.

StructureMap

A really nice container with simple XML configuration. But we had problems if the container must instantiate WPF-controls.

LightCore

Also a really nice container with simple XML configuration. But it seems that there is no way to specify distinct implementations which are choosable by a key.

Autofac

No external XML configuration possible.

Castle Microkernel

No external XML configuration possible.

Castle Windsor

My favourite over many years – with simple XML configuration and the possiblity to group implementations of the same contract which are choosable with a key.

But be carefully: after configure one container over a XML configuration, the folder with the to resolving assemblies seems to be from now on the one and only folder for searching assemblies. By instantiating a new container with an other XML configuration the assemblies could not found at an other folder.

We hat this problem by extending a framework with differnt plugins. All plugins uses Castle Windsor as an IoC-container. But when more than one plugin was activated the assemblies of the later loaded plugin could not be resolved from Castle Windsor.

So it could be necessary to compile a own version of Castle Windsor with an own key. That guarantees, that several Castle Windsor assemblies could be loaded in the AppDomain – and each assembly has then an own “searching folder”.

Spring.NET

untested