Running your software on the Jaxer server does not at all compel you to license your software under the GPL. Jaxer itself is licensed under the Gnu Public License version 3 (the GPL) in order to keep it free to use and distribute and extend, as long as distributed extensions to Jaxer itself are offered back to the community under the GPL. But software programs that run on top of Jaxer are not bound by the Jaxer GPL license. Indeed we place no restrictions on the software you run on top of Jaxer, in terms of licensing or anything else.

While most of Jaxer runs on the server, a small part of Jaxer is a client-side library that by default gets embedded in the pages Jaxer serves to the browser. Alternatively, Jaxer's configuration can be changed so pages it serves reference the client-side Jaxer library through a <script src="..."></script> tag. To alleviate any concerns you may have that such automatic distribution of a small piece of Jaxer might create a derivative work and thereby entangle your software with Jaxer's license, we're in the process of formulating an explicit "classpath" exception to the GPL license for Jaxer: that exception will state that we explicitly grant you an exception to distribute the client-side part of Jaxer and dynamically link it with your own software regardless of the terms of your software's license.

In short, please feel free to develop software for running on Jaxer without being concerned that Jaxer's license will somehow restrict your software's license. Jaxer's license does not affect any software you yourself write or obtain from a third party. Indeed, as long as you are not deriving software from Jaxer and redistributing that Jaxer-derived software, the only effect of the Jaxer license on you is to make sure Jaxer remains free and open to you.