A comment in the source JavaScript reads as follows:
* Copying and distribution of this file, with or without
* modification, are permitted in any medium without royalty
* provided the copyright notice and this notice are preserved.
* This file is offered as-is, without warranty of any kind.
Note that we minimize the JavaScript before serving it on member websites to make ad serving as fast and efficient as possible. This includes stripping all comments and extra white space from the script. The minimized JavaScript is provided under the same conditions as the linked source above.
