What are some alternatives?
When comparing Themida and Free UPX, you can also consider the following products
VMProtect - VMProtect Ultimate - All-In-One Solution For Software Licensing And Protection.
UPX - UPX (Ultimate Packer for eXecutables) achieves an excellent compression ratio and offers very fast...
Alienyze - Alienyze is a software packer and protection solution for windows executable files. Alienyze allows developers to easily protect their software against cracking and reverse engineering.
PELock - Software copy protection against reverse engineering with anti-cracking & anti-debugging techniques. Software license key system with time trial options.
ExEinfo PE - Packer, compressor detector / unpack info / internal exe tools.
LockBytes - LockBytes is a Lightweight DRM (Digital Rights Management) solution for licencing Windows executable files.