Vis is a highly efficient modal text editor that combines the modal editing paradigm of vi with the structural regular expression command language of Plan 9's sam. It is implemented in C99 with a Lua scripting API for configuration and extensibility. The core text engine uses a piece table with copy-on-write blocks and a directed acyclic graph for undo/redo, supporting multiple cursors and selections. Syntax highlighting is provided by a large collection of LPeg-based lexers (Scintillua), and the terminal UI supports both curses and raw VT100 backends. The editor includes companion tools (vis-menu, vis-open, vis-clipboard, vis-complete, vis-digraph) that follow Unix philosophy as separate executables. The codebase is well-structured with extensive testing including unit tests, fuzz testing, and compatibility tests against vim and sam. While primarily an application, the repository contains reusable data structures (crit-bit tree, dynamic buffer, text iterator) and a standalone digraph-to-Unicode converter that could be extracted for other projects.