Labs64 NetLicensing - Monetize your digital products and services
MIT License - A license from the Massachusetts Institute of Technology.
tl;drLegal - Software Licenses in Plain English
Simplified BSD License - Also known as the "2-clause" BSD license, this is a simplified version of an open source license created at the University of California Berkley.
Keygen - A dead-simple software licensing API built for developers
GPLv2 - Created for the GNU project, the GNU General Public License version 2 is the most popular free software license.