Does the LGPL ensure that programs that rely on my code admit it?

Question

Does the LGPL ensure that programs that rely on my code admit it? I read on Zed's blog something to that effect. (Link, section "I don't want to be ignored again"). Is it true?

Answer 1

It's best to learn reading libraries; with some exercise, it's not too difficult.

Wrt. your question: the LGPL 2.1 has the following clause:

[...] provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and distribute a copy of this License along with the Library.

So you need to include a copy of the license. As you also have to provide the source code, you also have to include the copyright notices in that source code.

Answer 2

The LGPL does include (in clauses 3 and 4) the requirements to:

Give prominent notice with each copy of the [[object code // Combined Work]] that the Library is used in it and that the Library and its use are covered by this License.

with minor exception for object code using only "numerical parameters, data structure layouts and accessors, or small macros, inline functions and templates (ten or fewer lines in length)". So the constraint to "admit" ("give prominent notice" of) the library's use does seem to be present.

Answer 3

Section 4 of LGPL

c) For a Combined Work that displays copyright notices during execution, include the copyright notice for the Library among these notices, as well as a reference directing the user to the copies of the GNU GPL and this license document.

This means that when user clicks "Help/About" and gets a window with copyrights, he should see your library there, among other copyrights.

Therefore, yes, LGPL requires admitting that your code was used to create the software.

However, noone ever reads copyright notices! What could help you is that your name was mentioned in official sites, in press releases and in the gossip going aroung about the software that used your code. Lesser GPL is no help for this.