Is a JAR file considered an executable or a storage/distribution medium?  Here is an excerpt from the LGPL:

-----

In addition, mere aggregation of another work not based on the Library with the Library (or with a work based on the Library) on a volume of a storage or distribution medium does not bring the other work under the scope of this License.

-----

After reading a little more, it appears that I would be able to use the firebirdsql.jar in my commercial application if the license was changed to LGPL.  Especially because I would consider a JAR to be a storage medium instead of an executable.  I also believe that subclassing portions of the library would not be considered a derivative work because the program that does the subclass is really just “using” the original library.  Changing the license is obviously not my decision because I have only contributed a microscopic portion of code but I would not have a problem if it was changed.

-Ken