“The main difference between the GPL and the LGPL is that the latter can be linked to (in the case of a library, ‘used by’) a non-(L)GPLed program, regardless of whether it is free software or proprietary software.[1] This non-(L)GPLed program can then be distributed under any chosen terms if it is not a derivative work. If it is a derivative work, then the terms must allow “modification for the customer’s own use and reverse engineering for debugging such modifications.” Whether a work that uses an LGPL program is a derivative work or not is a legal issue. A standalone executable that dynamically links to a library is generally accepted as not being a derivative work (in LGPL). It would be considered a “work that uses the library” and paragraph 5 of the LGPL applies.

A program that contains no derivative of any portion of the Library, but is designed to work with the Library by being compiled or linked with it, is called a “work that uses the Library”. Such a work, in isolation, is not a derivative work of the Library, and therefore falls outside the scope of this License.”