NURL

v0.66.0

A compiled language without a virtual machine, garbage collector, or interpreter — designed as a target for LLM code generation, with deterministic builds and native LLVM performance.

Start with NURL Open Playground

36,757lines of NURL in the compiler

1,102compiler test programs

232stdlib modules

11tested targets

63registry packages

Contributors

Hindurable

iljasrb

WHY NURL

Built for generated code

NURL keeps generated code easy to parse. Fixed arity removes precedence ambiguity, short dependency windows limit context, and the grammar fits on one page.

Regular prefix-arity grammar

Every operator has a fixed arity. There is no infix syntax or precedence table.

Local semantics

A token’s meaning depends on a short span of preceding tokens.

Single-owner memory

Values drop at scope exit. Borrow checking rejects use-after-move, double-free aliases, and escaping captures.

Deterministic compiler

Bootstrap compiles the compiler twice and requires identical LLVM IR from both runs.

LLVM-backed

One LLVM pipeline targets desktops, servers, WebAssembly, RISC-V, and embedded systems.

Self-hosting

The compiler is written in NURL and builds itself from source.

SYNTAX

Prefix notation, end to end

NURL uses OP ARG1 ARG2 …. There is no operator precedence or infix syntax.

Add two integers

@ add i a i b → i { ^ + a b }

( add 3 4 )     // → 7

FizzBuzz

: ~ i i 1
~ <= i 100 {
    ? == 0 % i 15 { ( nurl_print `FizzBuzz\n` ) }
    ? == 0 % i 3  { ( nurl_print `Fizz\n` ) }
    ? == 0 % i 5  { ( nurl_print `Buzz\n` ) }
    { ( nurl_println_int i ) }
    = i + i 1
}

See the language reference for generics, traits, pattern matching, errors, channels, compile-time evaluation, and async runtime support.

BENCHMARKS

Measured runtime performance

15 verified benchmarks compare NURL with C, Rust, Node, and Python. Each implementation must produce the same output before timing.

5 languagesGitHub Actions ubuntu-latest runnerMeasured 2026-09-19Benchmark sources →CI run →

Benchmark runtime in milliseconds; lower is better.
Benchmark	NURL	C	Rust	Node	Python
`lcg`20M-step 64-bit LCG + xorshift	39 ms	39 ms	39 ms	2,056 ms	5,224 ms
`packet_classifier`25M unpredictable branches	56 ms	56 ms	56 ms	162 ms	4,327 ms
`ring_write`20M ring-buffer stores	42 ms	42 ms	42 ms	67 ms	6,282 ms
`histogram_bins`20M binned increments	40 ms	41 ms	40 ms	67 ms	6,220 ms
`prefix_scan`1M 16-wide prefix scans	22 ms	22 ms	22 ms	64 ms	4,452 ms
`binary_search`5M lower-bound searches	39 ms	38 ms	37 ms	106 ms	5,967 ms
`sort_window`2M 8-element bubble sorts	27 ms	27 ms	27 ms	198 ms	11,534 ms
`bloom_filter`4M Bloom-filter queries	17 ms	18 ms	18 ms	2,866 ms	7,870 ms
`hash_join`5M hash-table probes	27 ms	28 ms	29 ms	3,450 ms	8,689 ms
`sieve`Sieve of Eratosthenes to 10M	21 ms	20 ms	21 ms	70 ms	3,748 ms
`fib`Recursive fib(35)	26 ms	31 ms	26 ms	131 ms	1,391 ms
`collatz`Longest Collatz chain below 100k	12 ms	12 ms	12 ms	52 ms	731 ms
`matmul`256x256 integer matrix product	33 ms	33 ms	33 ms	78 ms	3,245 ms
`json_parse`20 parses of a 64 KB document	10 ms	9.0 ms	12 ms	36 ms	39 ms
`nbody`500k n-body integration steps	25 ms	40 ms	24 ms	102 ms	3,081 ms

Median wall-clock time for the full process. Lower is better. NURL is highlighted only when its displayed time is lower than every other displayed time.

GET STARTED

Start with NURL

Try it in the browser

Write, build, and run NURL in your browser.

Open the Playground →

Install a release

curl -fsSL https://nurl-lang.org/install.sh | sh
irm https://nurl-lang.org/install.ps1 | iex

Install guide →

Build from source

git clone https://github.com/nurl-lang/nurl
cd nurl && ./build.sh

View the repository →

Editor support

The VS Code extension also works in Cursor and Windsurf, with diagnostics, completion, and formatting.

Editor guide →

TARGETS

One LLVM pipeline across targets

The compiler emits target-agnostic LLVM IR for desktop, server, browser, unikernel, and embedded targets.

Linux x86_64

Windows x86_64

macOS x86_64 and ARM64

FreeBSD x86_64

WebAssembly

Linux ARM64

Linux RISC-V64

Unikernel x86_64, ARM64, and RISC-V64

Milk-V Duo

ESP32 Xtensa

ESP32-C3/C6

Embedded hardware. NURL runs an HTTP file server on the Milk-V Duo and drives ESP32 GPIO through memory-mapped registers.

Browser builds. The playground compiles to wasm32-wasi in your tab and can cross-compile downloadable native binaries.

Bootable programs. The unikernel path links NURL programs without a host OS for x64, ARM64, and RISC-V targets.

STANDARD LIBRARY

232 modules, included with the toolchain

The standard library is plain NURL source: core types, general-purpose modules, and optional higher-level integrations.

Network

TCP, UDP, TLS, HTTP/1.1, HTTP/2, WebSocket, MQTT, SMTP, and peer-to-peer networking.

Data

JSON, TOML, YAML, XML, MessagePack, CBOR, CSV, PostgreSQL, and SQLite.

Concurrency

Threads, mutexes, channels, atomics, and a stackful M:N async runtime.

Core

Collections, arbitrary-precision numbers, regex, crypto, compression, UUIDs, paths, and processes.

AI and MCP

Anthropic API support plus MCP clients, servers, sessions, and registries.

Tooling

LSP, formatter, documentation tools, test and benchmark runners, and a differential fuzzer.

Browse the standard library →

PROJECTS

NURL projects

The compiler itself

A self-hosting compiler that produces identical LLVM IR in two compilation rounds.

Explore →

A Game Boy emulator

A complete DMG emulator compiled to WebAssembly for the browser.

Explore →

The playground backend

NURL serves the playground, build service, MCP endpoint, and package registry.

Explore →

Examples

Examples include Game of Life, HTTP/2, MCP servers, agents, and embedded targets.

Explore →

PACKAGES

Packages, one command away

The registry supports semver ranges, reproducible lockfiles, and signed tarballs verified by nurlpkg before unpacking.

nurlpkg search whisper
nurlpkg install nq
nurlpkg add tensor
nurlpkg publish

Browse the registry →

nurllama

whisper

onnx

tensor

grad

yoloe

nwasm

image

MCP SERVER

NURL tools for agents

Connect an MCP client to build, run, and cross-compile NURL without a local toolchain.

claude mcp add --transport http nurl https://play.nurl-lang.org/mcp

Read the MCP setup guide →

REFERENCES

Source, specification, and release history

Documentation

Guides and language reference for installing, writing, and running NURL.

Read the docs →

README

A repository overview of the language, runtime, and build pipeline.

Open README →

Formal grammar

The versioned EBNF grammar and historical snapshots.

Open grammar →

Changelog

A release-by-release record of changes.

Read changelog →

Roadmap

Current work and plans toward 1.0.

Read roadmap →

Package registry

Browse packages, source, and generated API documentation.

Open registry →