I suppose one could argue that as TooN is all templates, the terminology
of "linking this library" doesn't really apply though.
I looked at the LGPL V3. It is much shorter than the old GPL or LGPL. I don't
really understand clause 2. Clause 3 says that (for TooN at any rate):
a) Give prominent notice with each copy of the object code that the Library
is used in it and that the Library and its use are covered by this License.
OK, that's fine. Even the BSD license says the copyright notice must be
preserved. Though I'm not sure what counts as prominent. It also says:
b) Accompany the object code with a copy of the GNU GPL and this license
document.
So, your code (ie not TooN) may be conveyed "under terms of your choice", but
you have to include a copy of the LGPL and GPL for reference. I believe that
you have to include the GPL because of clause 2 says it can always be
relicensed under the GPL.
Other than that, the LGPL3 is simple.