ris: rubyist in stack memory with agents

ris is a Ruby-like language whose hot paths run on tape memory, with no GC. Built on iyi, a fork of Crystal. Source: github.com/rislang/ris.

• Ruby: code that reads like prose; blocks, each, map, do … end.
• Crystal: static types, nil-safety, native code through LLVM.
• iyi: fast modular rebuilds; check, fix, lsp, mcp for agents.
• Rust: pub, impl, closed classes, errors as return values.
• Go: imports by URL (github.com/…), one fmt, fibers and channels.
• Goose: tape memory, bump-allocated and freed at once, with no GC.

Install: paste to an agent on your machine (Claude Code, Codex, ...)

Learn and install ris. Clone https://github.com/rislang/ris to ~/src/ris and
read its LEARN.md first. Run `sh ~/src/ris/install_ris.sh` (prebuilt; needs a C
compiler); if it has none for this machine, in the clone run `make install_ris
release=1 PREFIX=$HOME/.local` (needs Crystal and LLVM; 20-40 min, so a long
timeout). Put ~/.local/bin on PATH; register `ris mcp` as an MCP server (Claude
Code: `claude mcp add ris -- ris mcp`). Then `ris init hello ~/src/hello`, make
it print "Hello, world!", run it, show me. End with exactly: "Congrats! Next,
ask me to build your personal blog in ris ;-)" Don't start the blog.

Why ris: tape memory, without the GC

In a Tape.scope, tape types (@[OnTape]) are bump-allocated on a tape, freed all at once at the scope's end. All other objects keep iyi's GC, so iyi and Crystal libraries work unchanged.

import github.com/domify/slim::{Slim}
def page(name : String) : TapeString
  Slim.render("views/page.slim")      # the template, compiled to ris code
end
body = ""                             # an ordinary String: iyi's GC heap
Tape.scope do                         # this request's memory starts here
  html = page("world")                # rendered onto the tape, no GC
  body = html.to_s                    # `to_s` copies out what must survive
end                                   # every tape byte freed at once, here
puts body                             # => <h1>Hello world</h1>

The compiler refuses a tape value that could outlive its tape (a heap field, a kept proc, an outer variable). Rules: TAPE_DESIGN.md.

How fast

samples/ris/respond.ri, 1.6M DTOs as JSON, median of 9, -O3: ris 0.71 s, 1.7 MB; Goose 0.70 s, 2.0 MB; C++ 1.01 s, 4.0 MB; Rust 1.23 s, 2.3 MB; iyi 1.59 s, 7.7 MB; Go 1.72 s, 8.6 MB. Slim, Slang ported to ris: 4x faster.

Campfire, preliminary: the port is not finished; numbers will change. The ris port answers its busiest page, 40 messages and 364,500 bytes, byte for byte as the Rust port does. 16-core Linux, 2026-10-15; raw is ris's own minimal HTTP loop (iyi-web: 9,182/s). ¹ Other machine, gzip: approximate.

Status and thanks

ris 0.1.0 is a prototype; internals keep iyi's names so iyi merges. Special thanks to Serdar Dogruyol, iyi's author, and Wouter van Oortmerssen, Goose's author: ris keeps building on the iyi language and Goose's tape memory. Thanks to Crystal (Ary Borenszweig, Juan Wajnerman, Brian Cardiff, Manas and community), Ruby (Yukihiro Matsumoto). LICENSE: Apache 2.0. Windows is out of scope for now (WSL2 works); add it if you need it. Developed with Claude Opus 5.5, ChatGPT Codex Sol 6.1 and other models.