# rio **Back to the future.** A lightweight IDE in the spirit of '90s desktop software. - A plain-text editor with git and an AI agent. Nothing more. - Written from scratch in Tcl/Tk. Inspired by Notepad++, Emacs and VS Code. - Windows 2000 looks, client/server inside: edit locally or on another box. [Website](https://rio.skylm.org/) · [User manual](docs/index.md) · [Changelog](CHANGELOG.md) · [Source](https://github.com/jlsksr/rio) · [Issues](https://github.com/jlsksr/rio/issues) ## Status Alpha. Release **0.4.0**, 2 October 2026. Used daily by its author. | Platform | State | | -------- | ----- | | Linux | Developed here. Suite passes. | | Windows 11 | Suite passes; last run 2026-09-17. Has driven a Linux core over SSH. | | macOS | One run, 2026-09-29: suite passes. Homebrew and MacPorts untried. | | BSDs | Design target. Never run. | - **Interfaces will change.** Highlighters are stable. The provider and editing-mode contracts are not; 1.0.0 waits for them. - **Limitations:** [CAVEATS.md](CAVEATS.md). - **Report** bugs, and anything that confused you. ## Install ```sh git clone https://github.com/jlsksr/rio.git && cd rio ./install-unix.sh # macOS: install-macos.sh Windows: install-windows.ps1 rio [file ...] ``` - Installs Tcl/Tk, tcllib and tcltls. Adds a `rio` command, an icon and a menu entry. - Nothing is compiled. Nothing is written outside your account. - Server mode, Windows, troubleshooting: [INSTALL.md](INSTALL.md). ## What it does Detail is in the [user manual](docs/index.md); `F1` opens it inside rio. - **Editing** — tabs, undo by the word, line numbers (absolute or relative), optional wrap, a right-click menu. Encoding and line endings are preserved. A file changed on disk reloads, or asks if you have unsaved edits. - **Recovery copies** — every changed file gets a copy outside the project, offered back on the next open. [More](docs/editor.md#keeping-your-unsaved-changes). - **Find and replace** — `Ctrl+F`. Live highlighting, a match count; case, whole-word and regex toggles. Replace All is one undo step. - **Project search** — `Ctrl+Shift+F`. The project on disk, every open document, or the current one. Replace works across the same scopes. - **Split editor** — `Ctrl+\`. Two groups, each with its own tabs. Drag a tab to reorder it or move it across. - **Files and git** — a project tree with create, rename and delete. Git status, diff, stage, unstage, commit and discard. - **Compare view** — two documents side by side, differences coloured. - **The agent** — a chat pane. Providers install as extensions: **Claude**, and **OpenAI-compatible** for ChatGPT or your own server (Ollama, llama.cpp, vLLM, LM Studio). Every edit and every command waits for Approve or Reject, unless you trusted that command. **Plan mode** only reads, then presents a plan. Its prompts are Markdown files on disk. - **Syntax highlighting** — 33 languages, coloured from the theme. One file each in `syntax/`; override in `~/.config/rio/syntax/`. - **Themes, fonts and keys** — themes switch live (default, Solarized Dark and Light, Plan 9 Acme). Pick the document font; zoom with `Ctrl+scroll`. Every shortcut is remappable. - **Editing modes** — Windows built in; Emacs and vi install as extensions. Column editing: `Ctrl+Shift+drag`. - **Sessions** — open files, the active tab, the unfolded tree and view preferences come back, per project. - **Remote** — run the core on another box, tunnel in, then `rio --connect 127.0.0.1:7711 /path/on/server`. Files, git, search, the agent and your API key stay there. - **Extensions** — highlighters, themes, editing modes and providers, from repositories you choose. Still to come: streamed command output, the terminal frontend, packaging. See [ROADMAP.md](ROADMAP.md). ## Extensions and repositories - **No marketplace.** A repository is a plain directory served over HTTP or HTTPS, as Debian does it. Add its URL under ***Extensions ▸ Browse…***. - **rio's own repository is pre-filled.** Remove it if you like. - **Provenance.** Every install records its repository and version. Same name in two repositories: both are listed, you choose. - **Code is called code.** Installing it says so, beside the URL you trust. Themes are data, never executed. - **Signing.** A publisher signs one list of hashes with stock OpenSSH. rio verifies it, then every file it fetches. A new or changed key waits for your yes, as `ssh` does. Each extension is marked *signed*, *unsigned* or *unverified*. - **Updates.** Versions are [semver](https://semver.org/). A row shows `[1.1.0 → 1.2.0]`. rio never updates on its own, and only from the repository an extension came from. - **Publish your own:** three text files. [CONTRIBUTING.md](CONTRIBUTING.md#extension-repositories). ## How it is put together ``` rio-gui (Tk) rio-tui (Ck, deferred) any other client │ │ │ └──── JSONL: request · response · event ───────┘ a pipe to a core it spawns, or a socket (--connect) │ ┌────────────┴─────────────┐ │ rio-core pure Tcl, no Tk│ │ documents · undo · files │ │ git · agent · sessions │ └──────────────────────────┘ ``` - **All logic is in the core.** A frontend is a thin view. - **One channel,** local or remote. No in-process path. - **Terminal frontend:** deferred. A spike proved Ck can carry it. ## By the numbers *Snapshot of 2026-09-26. Nothing checks these.* - **~30,700 lines of Tcl** in 91 files: core ~9,000, GUI ~13,900, highlighters ~4,500; providers, modes and plugin runtime ~3,000. - **~27,300 lines of tests**, 3,949 checks. - **3 runtime dependencies:** Tcl/Tk, tcllib, tcltls. No build step. `tkdnd` is optional. - **132 decisions**, each an [ADR](adr/README.md) with its reasoning. - **587 commits**, 2026-06-24 to 2026-09-26, all agent-assisted. Judge it yourself: run the suite, read the decisions. ## Documentation | Document | Holds | | -------- | ----- | | [docs/](docs/index.md) | **The user manual.** Also `F1`. | | [INSTALL.md](INSTALL.md) | Install scripts, local and remote, troubleshooting | | [CHANGELOG.md](CHANGELOG.md) | What changed, newest first | | [CAVEATS.md](CAVEATS.md) | Rough edges, platform differences | | [ROADMAP.md](ROADMAP.md) | Candidates, gaps, deferrals | | [CONTRIBUTING.md](CONTRIBUTING.md) | Toolchain, layout, tests | | [adr/](adr/README.md) | Every decision and its why | | [AGENTS.md](AGENTS.md) | Instructions for coding agents | | [WINDOWS.md](WINDOWS.md) | rio on Windows 11 | | [RELEASING.md](RELEASING.md) | Release gates | | [CODE_OF_CONDUCT.md](CODE_OF_CONDUCT.md) | What is expected of everyone | | [LICENSE](LICENSE) | MIT, in full | Config is one file per concern under `~/.config/rio/`: [reference](docs/preferences.md#where-everything-lives). ## Credits The icon is Christ the Redeemer, for the name. Own artwork (jka, made with ChatGPT); provenance in `rio-gui/icons/sources/README.md`. ## License MIT, no warranty. See [LICENSE](LICENSE). Copyright © 2026 Julius Kaiser. One licence covers the whole tree.