From the help handbook FAQ:
All TDE libraries are available under the LGPL making commercial software
development for the TDE desktop possible, but all TDE applications are
licensed under the GPL.
Is everything in TDE now fully GPL or do LGPL remnants remain?
Darrell
I have not changed the original licenses at all; if the TDE libraries were
LGPL as of KDE 3.5.10 then that is what they remain now.
Tim