GNU Affero GPL: Second Draft

One of the vexed questions in the free software world is what should be done about software as a service, when the service is based on free software:

All versions of the GPL allow people to use modified version of the software privately without being obliged to make their modified source code available to anyone. When people put software on a public server, the question is less clear: is that private use or public use? This was called the "software as a service" issue, or "SaaS".

The FSF's answer is a special licence, known as the GNU Affero GPL, which is now in its second draft.