Appendix - GIMP 2.6 for Photographers: Image Editing with Open Source Software - page 352

5.3.2 Downloading and Installing GIMP 2.7
For Linux users, GIMP 2.7 is only downloadable as source code. Thus, Linux
users have to compile the application themselves. RPMs and other installation
packages are not available. Developer's versions are sporadically available for
Windows (*-setup.exe) . Linux and Windows users can find the source code or
setup binaries on the website of SourceForge:
http://sourceforge.net/projects/gimp-win/
When installing GIMP 2.7, you should bear in mind that if you have an
older GIMP version installed and want to continue using it, you have to change
the file path when installing the developer version. For Windows, instead of
the default path C:\Program Files\GIMP-2.0 , apply the path C:\Program Files\
GIMP-2.7 when installing the developer version.
At any rate, it isn't easy to get the developer version to run. The developers
point out that whether it runs at all is questionable. Possibly only one version
will run. Any changes on the operating system could have an impact on
the functionality of your entire computer. If you want to use the developer
version, you should definitely make backups of your hard disk, including the
operating system and your installed programs. This author, as well as the
developers themselves, deny all responsibility in the case of damages inflicted
on your computer or on the installed programs through the installation of the
developer version, even if you have followed the directions given here.