secure defaults and a great developer experience.
It's built on V8, Rust, and Tokio.
- Provides web platform functionality and
adopts web platform standards. For example using ES modules, web workers, and
- Secure by default. No file, network, or environment access unless explicitly enabled.
- Supports TypeScript out of the box.
- Ships a single executable (
- Provides built-in development tooling like a code formatter
deno fmt), a linter (
deno lint), a test runner (
deno test), and a language server for your editor.
- Has a set of reviewed (audited) standard modules that are guaranteed to work with Deno.
- Supports the use of existing npm modules
Deno aims to be a productive and secure scripting environment for the modern programmer.
Deno will always be distributed as a single executable. Given a URL to a Deno program, it is runnable with nothing more than the ~31 megabyte zipped executable. Deno explicitly takes on the role of both runtime and package manager. It uses a standard browser-compatible protocol for loading modules: URLs.
Among other things, Deno is a great replacement for utility scripts that may have been historically written with Bash or Python.
- Ship as just a single executable (
- Provide secure defaults.
- Unless specifically allowed, scripts can't access files, the environment, or the network.
- Be browser-compatible.
do not use the global
Denonamespace (or feature test for it), ought to also be able to be run in a modern web browser without change.
- Provide built-in tooling to improve developer experience.
- E.g. unit testing, code formatting, and linting.
- Keep V8 concepts out of user land.
- Serve HTTP efficiently.
Other key behaviors
- Fetch and cache remote code upon first execution, and never update it until
the code is run with the
--reloadflag. (So, this will still work on an airplane.)
- Modules/files loaded from remote URLs are intended to be immutable and cacheable.