Quick License Manager - Quick License Manager (QLM) is a license protection framework that creates professional and secure license keys to protect software against piracy.
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.
LicenseSpring - Reliable and easy to use License-As-A-Service (LaaS) for for any software application
LicenseWatch - License Management