GIMP 2.6.6 is a bug-fix release in the stable GIMP 2.6 series. This release contains an important fix for compiling GIMP against the recently released GTK+ 2.16. Please have a look at the NEWS file for a list of other changes.
As usual, the source can be downloaded from ftp.gimp.org. Binary packages for the various supported platforms should become available soon; please check the Downloads section.
An update of the GIMP user manual is available. The gimp-help-2.4.2 tarball can be downloaded from ftp.gimp.org. Users should wait until this release has been packaged in more easily installable form for their platform.
This release is still focused on GIMP 2.4. Work has started on updating the user manual for GIMP 2.6. If you want to help, have a look at docs.gimp.org.