Submitted via IRC for TheMightyBuzzard
Light Table is a free, customizable, functional, and open-source IDE with a modern User Interface, plugin support, command pane, and connection manager
I'll stick with (g)vim personally but there's probably a few of you who'll find this interesting enough, if only to rag on it in the comments.
Source: https://www.fossmint.com/light-table-next-generation-open-source-ide-editor/ [fossmint.com]