Common Public Attribution License

The Common Public Attribution License ("CPAL") is a free software license approved by the Open Source Initiative in 2007. Its purpose is to be a general license for software distributed over a network. It is based on the Mozilla Public License, but it adds an attribution term paraphrased below:
The CPAL also adds the following section discussing "network use" which triggers copyleft provisions when running CPAL licensed code on a network service and this way closing the so-called ASP loophole:
The Debian project found the license to be incompatible with its Free Software Guidelines (DFSG) because of its attribution requirement.