一个基于Qt的类库版权声明看不懂，见笑了 [复制链接]

就想问一下按照这个版权声明，这个类库里有什么东西是不能免费使用的吗？这个版权声明是在LGPL上作了些小改动的：

                  Qwt License
                  Version 1.0, January 1, 2003

The Qwt library and included programs are provided under the terms
of the GNU LESSER GENERAL PUBLIC LICENSE (LGPL) with the following
exceptions:

  1. Widgets that are subclassed from Qwt widgets do not
    constitute a derivative work.

  2. Static linking of applications and widgets to the
    Qwt library does not constitute a derivative work
    and does not require the author to provide source
    code for the application or widget, use the shared
    Qwt libraries, or link their applications or
    widgets against a user-supplied version of Qwt.

    If you link the application or widget to a modified
    version of Qwt, then the changes to Qwt must be
    provided under the terms of the LGPL in sections
    1, 2, and 4.

  3. You do not have to provide a copy of the Qwt license
    with programs that are linked to the Qwt library, nor
    do you have to identify the Qwt license in your
    program or documentation as required by section 6
    of the LGPL.


    However, programs must still identify their use of Qwt.
    The following example statement can be included in user
    documentation to satisfy this requirement:

      [program/widget] is based in part on the work of
      the Qwt project (http://qwt.sf.net).

问了一下同学，他说大概意思是不能派生和静态连接，不过动态连接是可以的

我觉得这个意思是允许自由派生， 自己写的程序可以不公开。 只有在你的qwt库修改过的情况下需要公布qwt修改的源码，其他的使用qwt（动/静）开发的程序都不需要公布源码。