User Guide

Kaappi is a Scheme you can install in one command and start using immediately. It implements the full R7RS-small standard with 178 SRFIs, C FFI, and a package manager — everything you need to write real programs.

Getting started

1. Installation — one-line install or build from source
2. Your First Program — run a file, explore the REPL
3. Scheme Tutorial — learn Scheme from scratch with runnable examples

Prefer the browser? Try the interactive tour or the playground — no install needed.

Prefer video? The @KaappiScheme screencasts cover the language, the ecosystem, and the tooling in three short seasons.

Language

• Language Reference — syntax lookup for every form and feature
• Libraries — importing libraries and what's available
• Library Authoring — creating your own libraries with define-library
• SRFI Support — all 178 supported SRFIs at a glance
• Concurrency — green threads (fibers) and OS threads (SRFI-18)

Tooling

• REPL Guide — commands, history, tab completion, reverse search
• CLI Reference — command-line flags and standalone binaries
• Debugging — stepping debugger, profiling, disassembly, performance tips
• Editor Support — VS Code, Neovim, Emacs, Helix setup

Extending

• C Extensions — calling C via FFI and packaging C extension libraries
• Zig Extensions — writing extensions in Zig with memory safety and cross-compilation

In production

• Security — SQL injection, XSS prevention, safe FFI, sandbox mode
• Deployment — standalone binaries, WebAssembly, Docker, systemd, reverse proxy
• Migrating from Other Schemes — differences from Racket, Guile, Chicken, and Common Lisp
• Troubleshooting — common errors, pitfalls, and how to fix them