A modal editor, Kakoune uses keystrokes as a text editing language, for powerful and flexible text editing - doing things faster and in fewer keystrokes. Multiple selections allow for sweeping changes with very few commands, and it's orthogonal design assures predictable operation.
Modal editors generally have a steep learning curve, but that is rewarded with powerful and fast text manipulation skills. Kakoune helps level the leaning curve with strong focus on interactivity, showing immediate and incremental results.
On a system running the stable branch, first accept the installation of from the testing branch:
emerge --ask --autounmask=y --autounmask-write app-editors/kakoune
Validate the changes:
emerge --ask app-editors/kakoune