Keygen - A dead-simple software licensing API built for developers
Labs64 NetLicensing - Monetize your digital products and services
WebCops - With more than 30 years of experience in copy-protection and encryption. Link Data is making protection for CD, DVD, USB and web on Windows, Mac and Linux.
VMProtect - VMProtect Ultimate - All-In-One Solution For Software Licensing And Protection.
Open iT LicenseAnalyzer - Open iT LicenseAnalyzer is a software usage metering and optimization tool that provides an enterprise-wide overview of installed software programs managed by most software license managers.
LockBytes - LockBytes is a Lightweight DRM (Digital Rights Management) solution for licencing Windows executable files.