The computer code that comprises UCSF Chimera is protected by copyrights held by The Regents of the University of California (“The Regents”) and is licensed for non-commercial use at no cost by The Regents. You must agree to the terms and conditions of use as specified in the UCSF Chimera non-commercial license agreement before you will be permitted to download Chimera.

COMMERCIAL USE OF UCSF CHIMERA IS COVERED BY A SEPARATE WRITTEN LICENSE AGREEMENT. Commercial licensing costs depend on the number of users. For details and instructions on how to obtain a license, please see Chimera Commercial Licensing.

Chimera extension developers please note: The purpose of the Ownership and Assignment of Copyright section of the license agreement is to protect The Regents' exclusive rights as copyright holder in the existing code and derived works based on this code. It does not cover original code developed by others. Extensions to Chimera and ChimeraX that are not modifications, improvements, or derivatives of code copyrighted by The Regents are considered the property of their authors. (The programming examples we provide are explicitly NOT copyrighted!)