The original software behind CDDB was released under the GNU General Public License, and many people submitted CD information thinking the service would also remain free. The license was later changed, however, and some programmers complained that the new license included certain terms that they couldn't accept: if one wanted to access CDDB, one was not allowed to access any other CDDB-like database (such as Freedb), and any programs using a CDDB lookup had to display a CDDB logo while performing the lookup.[6]