Earlier this week, Jehan Pagès delivered on his promise to create symmetry painting mode for painting tools in GIMP. The code is now available in a dedicated development branch to be later merged for v2.10.

The new mode is supported by all brush-based tools (Paintbrush, Pencil, Eraser, Smudge, Clone etc.), as well as by the Ink tool. Jehan also posted a video demonstration of the current implementation:

Symmetry mode for painting tools is the second community-sponsored development project for GIMP endorsed by the GIMP team (the first being improved interpolation methods). The project wasn't 100% funded until several months ago, so Jehan spent most of the time doing what he had been doing for GIMP before: fixing bugs.

As you can see, the current implementation goes beyond the original proposal: there are multiple kinds of symmetry, and they are all configurable. Moreover, Jehan is considering an implementation of pluggable symmetries, although don't take it for a promise just yet.

Despite hard evidence a lot of people still treat GIMP as a generic image editor rather than something suitable for digital painting. So the new feature could be another reminder that there is more to GIMP than cropping, retouching, and color grading.

There are no known builds of this development branch yet. If you are curious to try the symmetry mode for painting tools, you need to build babl and GEGL from Git master, then clone Git repository of GIMP and checkout the 'multi-stroke' branch, then build it. Or you could wait till the new feature ends up in the main development branch of GIMP (apparently, soon) and thus becomes available in nightly builds for Windows and Ubuntu, as well as in builds at partha.com.

Additionally, if you've been wondering what the GIMP team has been busy with lately, here's an extensive 2014 report.