deno

Linux & Mac Windows

A secure TypeScript runtime built on V8

  • Supports TypeScript 3.1 out of the box. Uses V8 7.1. That is, it’s very modern JavaScript.

  • No package.json. No npm. Not explicitly compatible with Node.

  • Imports reference source code URLs only.

    import { test } from "https://unpkg.com/deno_testing@0.0.5/testing.ts";
import { log } from "./util.ts";

    Remote code is fetched and cached on first execution, and never updated until the code is run with the --reload flag. (So, this will still work on an airplane. See ~/.deno/src for details on the cache.)

  • File system and network access can be controlled in order to run sandboxed code. Defaults to read-only file system access and no network access. Access between V8 (unprivileged) and Rust (privileged) is only done via serialized messages defined in this flatbuffer. This makes it easy to audit. To enable write access explicitly use --allow-write and --allow-net for network access.

  • Single executable:

    > ls -lh target/release/deno
-rwxr-xr-x  1 rld  staff    48M Aug  2 13:24 target/release/deno
> otool -L target/release/deno
target/release/deno:
  /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1252.50.4)
  /usr/lib/libresolv.9.dylib (compatibility version 1.0.0, current version 1.0.0)
  /System/Library/Frameworks/Security.framework/Versions/A/Security (compatibility version 1.0.0, current version 58286.51.6)
  /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 400.9.0)
>

  • Always dies on uncaught errors.

  • Aims to support top-level await.

  • Aims to be browser compatible.

Install

With Python:

curl -L https://deno.land/x/install/install.py | python

With PowerShell:

iex (iwr https://deno.land/x/install/install.ps1)

Note: Depending on your security settings, you may have to run Set-ExecutionPolicy RemoteSigned -Scope CurrentUser first to allow downloaded scripts to be executed.

Try it:

> deno https://deno.land/thumb.ts

See also deno_install.

Status

Under development.

We make binary releases here.

Docs are here.