Slate Text Editor

Slate is a free, open-source Notepad replacement for Windows and Linux (Raspberry Pi included) that opens files of any size instantly. Nothing is loaded up front: only what's on screen is read and drawn, so logs, database dumps and JSON exports of hundreds of megabytes open, scroll and search like small files. An 810 MB JSON file is on screen in 14 ms, and all 435,571 matches of a search in it are counted in 0.3 seconds.

Tabs and unsaved changes come back after a restart, big files included. It has find and replace with regular expressions, syntax colors for 52 languages, JSON and XML format, minify and check with a path bar and a structure panel, line tools (sort, remove duplicates, trim), dark and light themes, and it keeps the file's encoding and line endings.

On Windows it's a single signed exe that updates itself; on Linux it's a .deb with its own apt repository.