libxxf86vm1 6.8.2-10.4 (amd64 binary) in ubuntu hoary

 libXxf86vm provides an interface to the XFree86-VidModeExtension extension,
 which allows for client programs to get and set the current gamma value, as
 well as retrieving, modifying, deleting, and selecting mode lines, and other
 advanced information. For most purposes, libXrandr (see the libxrandr1
 package) should suffice.