What it is.
Koru is a pre-alpha Zig-superset systems programming language. Every .kz file is valid Zig; Koru constructs are marked by a ~ leader. The distinctive design move is event continuations with mandatory branch handling — events declare their inputs and possible output branches in advance, and invoking an event requires explicitly handling each branch. Phantom typing tracks compile-time resources; purity is tracked through the type system; the compiler is metacircular (Koru compiles to Zig). The author is anonymous behind the korulang GitHub org and Twitter account; the project’s site lists Claude Opus 4.1–4.5 and Sonnet 4.5 as the models that authored the compiler itself.
The site’s tagline is intentionally tongue-in-cheek: “The Hyper-Performant AI-First Postmodern Zero-Cost Fractal Metacircular Phantom-Typed Auto-Disposing Monadic Event Continuation Language with Semantic Space Lifting and Event Taps.” Underneath the buzzword cascade, the README is candid about state: “Pre-Alpha — Koru is pre-alpha. It has only ever been compiled on a single computer. Use and testing at your own risk.” No SKILL.md, AGENTS.md, MCP server, or structured-JSON diagnostics ship. The closest planned agent-facing surface is the Compiler Control Protocol (CCP), described as “soon” — a Koru-internal proposal, not the Model Context Protocol.
Why it’s here.
The catalogue includes Koru as a marker of the position where “AI-First” became a tagline trope. The architectural claim (event boundaries provide bounded contexts that aid AI reasoning) is a real design move; the buzzword-cascade tagline is real satire; and the catalogue’s unclassified bucket exists for projects whose camp placement isn’t yet evidenced by shipped agent-authoring machinery. Companion to Valea and Spec: a real project with substantive design, candidly aware of its pre-alpha state, where the “AI-First” claim is a language-architecture argument rather than a tooling commitment. The pre-alpha disclosure quoted above is the editorial centre of gravity — the rest of the entry exists to give it context.
- Valea unclassified Companion in the unclassified bucket. Both stake an 'AI-native systems programming language' position with substantive design proposals but limited public evidence and no agent-authoring machinery shipped. Valea is a Rust MVP announced on Hacker News with JSON diagnostics planned; Koru is a Zig-superset metacircular compiler with event continuations and an explicitly tongue-in-cheek marketing voice.
- Spec unclassified Adjacent unclassified entry on the 'architecture as AI-friendliness' axis. Spec proposes a two-domain IR for multi-agent collaboration; Koru proposes architectural primitives (event boundaries, mandatory branch handling) that aid AI reasoning at the language level. Both make architectural claims about AI-friendliness without shipping agent-authoring tooling.