Playground
Write Greengold, see errors and checked fixes as you type, and run the program, all in the browser. The real compiler runs on your machine; nothing is uploaded.
Loading the compiler…
Input for the program (stdin)
Programs run in your browser: print, strings, List, HashMap, and input work.
Threads, tasks, sockets, and files do not; to use them, install gg.
The first Run downloads the compiler once (tens of MB; your browser keeps it).
Editor: Ctrl+Enter runs, Tab indents (Shift+Tab outdents), Ctrl+/ comments lines, brackets and quotes close themselves, and Esc then Tab leaves the editor.