Kakoune

Multiple selections are the central way of interacting in Kakoune, with powerful handling primitives (regex matches, filtering, splitting, aligning, text objects etc). Kakoune implements several tools to help editing/writing text: contextual help, as-you-type completion, syntax highlighting for several programming languages. Text can be selected and modified at will in multiple ways, thanks to several primitives: selection rotation, case manipulation, indentation leveling. Users can extend the features of Kakoune or customize them to their liking with macros or hooks. With Kakoune, you can collaboratively edit the same file: all new windows created by the editor are clients, and can simultaneously modify the content of a file. As such, windows are fully under the control of your X11 window manager or can be managed in a single terminal through Kakoune's tmux support.