As the title says.

More context from Brad re: xunit's strong-named assemblies.

We strong-name xunit.dll, xunit.extensions.dll, and xunit.runner.dll.

The reason is simple: if you are strong naming something, then it must be linked against only things which are themselves strong named. We also ship our public and private key in the repository so that people can strong name it themselves, so we don't consider this to be any kind of security measure (nor should our users). If compilers didn't enforce "you are signed, therefore everything you link to must be signed", we never would've bothered.