This is only a plain english explanation of the GPL license. The terms of OpenACS license are those of the GNU GPL v2. This simpler description is provided for your convenience only, not as a substitute for the GPL.

All versions of OpenACS are available to you as follows:

• Anyone can use this software for any purpose, commercial or non-commercial.
• Anyone can modify this software in any desired way for private use, without redistributing any code. This means you can use and customize OpenACS to run any web site, commercial or non-commercial, without any requirement to contribute your modifications back to other OpenACS users. Of course, such contributions are welcome, but by no means required.
• Anyone can redistribute this software, in its original form or modified, as long as the distributed product comes with full source code and is also licensed under the GPL.
• Your web site content and the data contained in OpenACS database tables are not covered within this license, which means that they are yours to do whatever you wish with, and you are under no obligation to make this data available to anyone.