Thanks for the clarification. This sort of question is bound to come up as people stub their toes against the new license. There once was a time that LGPL was seen as “the debil” and GPL the true Open Source alternative. How times have changed.

“I was making the point that most open source project are pretty sloppy when it comes to adhering to the terms of other projects’ licenses.”

The spots of Ext JS that leverage YUI code are all doing so within the bounds of the Yahoo UI BSD license.

For example, the drag drop core code includes the same header in the file, as it did when ported from YUI:
/*
* These classes are derivatives of the similarly named classes in the YUI Library.
* The original license:
* Copyright (c) 2006, Yahoo! Inc. All rights reserved.
* Code licensed under the BSD License:
* http://developer.yahoo.net/yui/license.txt
*/

or in the ext-base.js file, which also leverages some older YUI code:

/*
* Portions of this file are based on pieces of Yahoo User Interface Library
* Copyright (c) 2007, Yahoo! Inc. All rights reserved.
* YUI is licensed under the BSD License:
* http://developer.yahoo.net/yui/license.txt
*/

Yes, you’re right. Sorry if my post gave the wrong impression. My larger point wasn’t about whether Ext JS was in violation of YUI’s license or not. Rather, I was making the point that most open source project are pretty sloppy when it comes to adhering to the terms of other projects’ licenses.

a) It’s okay to use YUI in a commercial product (as ExtJS does);
b) all forms of redistribution require the YUI license to be present;
c) regardless of how commercial products like ExtJS use YUI, the YUI community can always download and freely use YUI under the terms of its license.

-Eric