LGPL and DLLs

[Kelly Anderson]

The LGPL says that you can use an LGPLed library in a commercial setting. 
However, they also make this requirement that you have to be able to 
re-link the LGPL program into the proprietary program. My [IANAL] 
understanding of the LGPL's intent in the re-linking language is so that 
you can replace the part of a program that is under LGPL with a newer 
version, or your own version, without the proprietary company's permission. 
I kind of get what they are doing, trying to make the program semi-open, so 
that you can still change things that are part of the library.

If you put the LGPL library code into a DLL, and give instructions on how 
to construct that DLL (or the project already comes in DLL form in the 
first place) then is this generally understood to fulfill the re-linking 
requirements of the LGPL?

Assuming that the DLL is a solution to the re-linking issue, is the 
proprietary company then within it's rights to say, "If, however, you do 
replace this DLL with another version, you've gone off the reservation, and 
we can't provide technical support for you until you put a 'blessed' 
version of the DLL back into your installation."

It seems unfair to expect a closed source company to provide support for a 
DLL that has been changed by the end user under an open source license. The 
re-linking clause makes closed source shops nervous about using code 
licensed under the LGPL. (At least that's my personal experience.)

At the same time, it seems unwise for the open source community to refuse 
the help they could get from commercial "moles" who are willing to work on 
their software under the context of the LGPL, if they could  use it for 
commercial purposes.

-Kelly