Update: In a blog post issued shortly after this story posted, an unidentified member of SourceForge's community team wrote that, in fact, "this project was actually abandoned over 18 months ago, and SourceForge has stepped-in to keep this project current." That runs counter to claims by members of the GIMP development community.
The GIMP project is not officially distributed through SourceForge—approved releases are only posted on the GIMP project's own Web page. But Jernej Simoni, the developer who has been responsible for building Windows versions of GIMP for some time, has maintained an account on SourceForge to act as a distribution mirror. That is, he had until today, when he discovered he was locked out of the Gimp-Win account, and the project's ownership "byline" had been changed to "sf-editor1"—a SourceForge staff account. Additionally, the site now provided Gimp in an executable installer that has in-installer advertising enabled. Ars tested the downloader and found that it offered during the installation to bundle Norton anti-virus and myPCBackup.com remote backup services with GIMP—before downloading the installer authored by Simoni (his name still appears on the installer's splash screen).