What are the differences between Code Virtualizer and Themida?

Themida is a superset of Code Virtualizer. That is, Themida includes the same virtualization engine as Code Virtualizer plus it adds other protection options (encryption, compression, API-Wrapping, etc.).

Code Virtualizer is commonly used by developers that just want to fully obfuscate special (sensitive) code areas (like serial checks, trial/registration checks, etc.) but they don't want to apply compression, anti-debuggers, etc.

Code Virtualizer is also able to protect Windows device drivers and Linux/Mac x32/x64 applications, which are not supported by Themida.