Palm is being sued by Artifex Software over the PDF viewer in Palm's Pre smartphone, which may violate the GNU GPL. Artifex alleges that Palm has copied Artifex's PDF rendering engine, called muPDF, and integrated it into the Palm Pre's PDF viewer application without the proper licensing conditions. The entire application must be licensed under the GPL if muPDF is part of the application. It seems more and more cell phones are shipping with open source code, but in a closed manner.