Yep, send me $5000 or our lawyers will start a new branch in your city
Seriously, Xajax is under BSD license:
BSD license wrote:
Copyright (c) 2006, Jared White & J. Max Wilson
portions copyright (c) 2006-2008 by Joseph Woolley & Steffen Konerow
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
* Neither the name of xajax nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED
So, as long as you don't sell xajax is if it were your product and don't remove the copyright notice it's all ok. If you'r going to earn money with a product that makes use of xajax you should always keep in mind that: Donations keep open source developers happy