The doc-shooter is a small utility used to create screenshots of widgets for the GIMP API reference manuals. This utility isn't built by default, you need to explicitely compile it using make doc-shooter Taking the screenshots is also not part of the docs build. Instead, the images are created, and then copied by hand into devel-docs/libgimpwidgets/images. Ideally, the images should be taken once a release, and all images should be updated at the same time. A simple theme should be used to take the screenshots. The GTK+ docs team came up with the idea for this utility as well as some of the code to implement it.