Software service over a network
A new version of the GPL has been released to cover a gap where software is a service provided over a network. The Affero General Public License,is a variation of the General Public License.
The GPL treats software provided as a service as "a private use" of software, permitting the user to keep any changes private. However the Affero GPL lets programmers require users to download it when it's offered as a network service.
Such issues are becoming important as companies such as Google employ customized open-source software to run massive online businesses with no requirement for sharing.