Kakoune

Kakoune is a modal code editor that builds on vim-style keybindings to reduce the number of keystrokes needed for editing. It centers on multiple selections as its main way of interacting with text, allowing developers to manipulate many selections simultaneously using powerful primitives like regex matching, filtering, splitting, alignment, and text objects. The editor includes text editing tools such as contextual help, completion as you type, and syntax highlighting for multiple programming languages. It also provides advanced text manipulation capabilities including selection rotation, case transformation, and indentation adjustment. Users can extend and customize Kakoune with macros and hooks to suit their workflow.

Developed by mawww, Kakoune is written in C++ and released under the Unlicense, making it freely available for use and modification.