Why not adopt a copyleft license like the GNU General Public License (GPL)?
Jasig support the ideas behind “copyleft” and believe that free software should stay free. However, many of the communities and projects that Jasig regularly collaborates with currently avoid copyleft protection for their projects because they perceive it as a barrier to widespread adoption. Specifically, the “viral” nature of copyleft licenses like the GNU General Public License is viewed negatively by many. In the interests of continued symbiotic relationships with these projects and to promote adoption of Jasig projects as widely as possible, Jasig is not using copyleft licenses. Jasig does strongly encourage anyone who improves upon a Jasig project to contribute those changes back to the community. This is mutually beneficial since the community gets a better project and the contributor does not have to maintain a diverging codebase.
