Copyright (c) 2005 the JDBL Team (see AUTHORS file for a complete list).
The LGPL is a flexible, standard license designed to allow the use of JDBL in both open source and commercial projects. In a nutshell, it allows you to use an unmodified copy of JDBL as you see fit, but it asks that you contribute back your modifications. Please note that this places no restrictions on your application's code, just on your modifications to JDBL.
Using JTDS is considered to be dynamic linking, hence the use of JDBL does not affect the license of your application code. Moreover, any code generated by JDBL is considered to be yours, and is thus excempted from the provisions of the LGPL.
If you modify JDBL and redistribute your modifications, the LGPL applies, basically meaning that you'll have to make the modified version publicly available under the LGPL license too. This ensures that all users of the software have access to any future improvements, and builds a collaborative environment benefiting everbody.