l123 recreates the classic DOS-era spreadsheet experience — slash menus, three-line control panel, keyboard-first workflows, WYSIWYG icon panel, and all — on top of a modern formula engine with native .xlsx round-trip. Its interaction model targets Lotus 1-2-3 Release 3.4a for DOS (1993). Its compute and I/O layers are Rust, IronCalc, and UTF-8. git clone git@github.com:duane1024/l123.git cd ...