Contributors need to agree to the following "Terms and Conditions: "

- You may use, reproduce, and distribute modules, consisting of both the software and the associated documentation, freely for all nonprofit educational purposes.  You may also make any modifications to the module and distribute the modified version.  If you do, you must:
- Give the modified version a title distinct from that of the existing document, and from all previous versions listed in the "History" section of the associated documentation with or within a module.
- In the line immediately below the title, replace the existing text (if any) with the text "© YEAR  NAME", where YEAR is the year of the modification and NAME is your name.  If you would prefer not to copyright your version, then simply leave that line blank.
- Immediately below the new copyright line (even if you left it blank), add or retain the lines: Original version: name of module  © 2004  authors of module. See end of document for full modification history.
- Retain this "Terms and Conditions" section unchanged.
- Add to the "History" section an item that includes at least the date, title, author(s), and a description of the modifications, while retaining all previous entries in that section.

These terms and conditions form a kind of "copyleft," a type of license designed for free materials and software.  Note that because this section is to be retained, all modified versions and derivative materials must also be made freely available in the same way. This text is based on the GNU Free Documentation License v1.2, available from the Free Software Foundation at http://www.gnu.org/copyleft/ .