From JAXXWiki

JAXX is licensed under the BSD License. The BSD license is extremely permissive compared to many other open-source licenses, notably the GPL and LGPL. JAXX is completely free for both commercial and non-commercial use as long as you respect the terms of the BSD License.

BSD License requirements

In plain English, the major license requirements are:

• If you distribute any part of JAXX compiler or runtime (modified or unmodified) in source form, the original copyright notices in the source code as well as the JAXX LICENSE file must be preserved.
• If you distribute any part of JAXX compiler or runtime (modified or unmodified) in binary form, you must include the JAXX LICENSE file at an appropriate place in your documentation or overall license agreement.

That's it. Otherwise you are free to do anything you like with JAXX.

Friendly requests

As one developer to another, I (Ethan) do have a few requests to make regarding your use of JAXX. None of these requests are legally binding and you may feel free to ignore all of them (so long as you adhere to the BSD license above).

• Give appropriate credit. If you write a program that makes significant use of JAXX, a brief note to the effect of "This program uses the JAXX Framework (http://www.jaxxframework.org)" in the About dialog or similarly appropriate location would be greatly appreciated.
• Let me know you're using JAXX. Post a message in the forums announcing your program so that we can marvel at it. A bit of free publicity can't hurt.
• Contribute code changes. If you modify JAXX in a way that would be useful to others, send your changes to ethan@ethannicholas.com so they can be shared with the rest of the community.

Again, you are under no obligation to do anything but adhere to the BSD License. However, considering the hundreds of hours I have spent writing JAXX, I hope you will consider crediting JAXX in your application's About dialog.