The image mosaic plug-in for the GIMP is no longer supported or distributed. Mr. Robert Silvers, the holder of a patent related to the technology that was used in the plug-in, argued that the software would directly infringe his patent rights. It is not clear if the patent is applicable in this case. But I have neither the time, interest or money for legal action. So I complied with the cease and desist request.
PHOTOMOSAIC® is a registered trademark of Runaway Technology, Inc.
The photomosaic process is patented (US Patent No. 6,137,498) and
protected by the patent, copyright, and other intellectual property
laws of the United States and other major countries.