Lefty, and its dependent tools Dotty and Lneato, have been suspected unused for a long time. They were scheduled for removal, but we took a cautious and very slow approach to this given how pervasive Graphviz is and the limited visibility we have into its usage:
- 2021-09-25 make Lefty default to disabled in the build system¹
- 2022-01-16 disable Lefty in published graphviz.org packages²
- 2022-03-28 remove build system support³
This completes the final step of removing the code from the repository. It is still retained in the history, should anyone need access to it or need to build a past version of Graphviz with Lefty.
So far, we have only heard two notable reactions from the downstream world:
- Lefty disabling was not quite complete on the first attempt.⁴
- There has been an offer of assistance to maintain Lefty.⁵ No patches have yet emerged, but if and when they do we could feasibly reverse direction on this and reinstate Lefty and friends.