@edavies @clacke @lightweight as i understand it (and i've just spent the last hour checking), the LGPL only exists because there was some legal ambiguity as to whether linking to a dynamically-loaded library was derivation or not, which the LGPL resolves by explicitly saying "no, it isn't". but other than that, it *is* basically the GPL, and anything that does more than link to it is under the same obligations as a GPL'd program would be.
but in practice, one could take a GPL'd library, write a server around it that responds to incoming RPC requests by calling the exact functions and sending out their replies, release the code to that server, and use it to serve one's proprietary program with exactly the same results as an LGPL'd equivalent.
if only the industry had focused on making RPC/IPC fast enough that dynamic linking was seen as an unnecessary complication, the question wouldn't have arisen in the first place...