The AGPL license was designed to close what’s perceived by some as a loophole in the GPL license. The GPL is a popular free software license that guarantees anyone who has received a copy of the software the right to run, study, modify, and share it for free or for a fee. Distributors of GPL-licensed software are not allowed to place restrictions on the rights guaranteed by the license. For example, distributing the software under a non-disclosure agreement is forbidden.