ExtJS发布2.1版本，但是更改了License，希望大家就此展开讨论

我认为你再一次夸大了Ext原先许可证的问题。
说到底，Jack的意图是防止其他人做出一个基于Ext但是与Ext竞争的商业产品。

"If you plan to distribute Ext in a product that will be packaged or sold as a software development library, toolkit or plug-in-based framework (LIBRARY), we require that you work with us to establish a specific license that is appropriate. Use of the open source license terms in a LIBRARY is not permitted without explicit permission."

Because of this restriction, any point you have made about rights granted to you by the LGPL are invalid since we have explicitly denied you the right to use Ext under the open source LGPL license because you are distributing a LIBRARY. As stated above, this is why we have an intermediate license under which we distribute instead of the distributing directly under the LGPL.

...Releasing under straight LGPL was not option as a business. We tried that with version 1.0 and found out quickly that it enabled others (e.g. large commercial entities) to take our work, wrap it up and sell it as their own. With no mention of us at all. We, as a business with a full time team of talented developers can not exist under those circumstances. We would quickly become diluted and competing with ourselves!
That’s why Ext 1.1 introduced the Ext License instead releasing directly under LGPL. This however killed any open source usage. If we had a modified LGPL, it also would be the same scenario - a shared source license, not quite open source according to the critics attacking Ext JS.
In the end, we were faced with an identity decision - are we an open source company funded by commercial endeavors or a commercial company with a proprietary framework under a shared source license? Since we started we have been open source and that is the route we will continue on.
Best of luck with future projects.

至于说对于其他开源/自由世界的约束，也是不存在的，你大可以做一个基于Ext2.1的GPL项目去跟Ext竞争，只是你的商业模式被限制了。

For the (less than 10%) of people upset by the license change we are trying to find alternatives (such as a FLOSS exception) and new programs (such as start-up, small business and educational) to make the transition easy.
Comment by jackslocum — April 27, 2008

忍不住了，说两句：
听听adobe对ext开发核心人员（Jack/Brain）实时的录音采访（MP3,有兴趣的朋友可问小弟索取），
其中，Jack自己说过ext开发的部分原因：“for living”（表明解决生活费是开发EXT其中一个理由），
出来混的，能温饱是基本，
能够从这点出发，采用GPL协议看做自我作品的一种保护，大家都能理解

而且jack不是给大家留后路,见：

少于10%的人不欢迎这次许可的变动。我们将会为这些用户找出替代GPL的方案，就像MYSQL的另外条例， 具体是新的程序，像刚起步的，小商户和教育界的程序，可以使过渡更轻松。

I just want to clarify that the library
is going to continue open source and be free to use for everyone. I
will be adding an option for personal support and for people to pay
for a license (if they want to).

其实这种“酸溜溜”大可不必。。。相信jack这个人就可以了。 

这是jack当年还活跃在yahoo forum上的留言：

出处 http://tech.groups.yahoo.com/group/ydn-javascript/message/9497l
这就是作者的期许，作者的初衷，过多的怀疑只会让作者产生消极的作用（人心肉造）。
ext不比dojo,一早受到大厂宠幸，资金不成问题，将心比心，换转你是jack，一路下来，你是怎么会“又好又快地”发展？

Jack人很nice，
攻击JACK的人都是误会了的缘故