Deno (software): Difference between revisions

Deno
Original author(s)	Ryan Dahl
Developer(s)	Deno Land Inc and contributors
Initial release	May 13, 2018; 6 years ago
Stable release	2.0.2 / 18 October 2024; 31 days ago
Repository	github.com/denoland/deno
Written in	TypeScript, JavaScript, Rust, C++ (V8 bindings)
Operating system	Linux, macOS, Microsoft Windows
Type	Runtime environment
License	MIT License
Website	deno.com

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Deno (/diːnoʊ/^[5]) is a runtime for JavaScript, TypeScript, and WebAssembly that is based on the V8 JavaScript engine and the Rust programming language. Deno was co-created by Ryan Dahl, who also created Node.js.^[6]

Deno explicitly takes on the role of both runtime and package manager within a single executable, rather than requiring a separate package-management program.^[5]^[7]

History

Deno was announced at JSConf EU 2018 by Ryan Dahl in his talk "10 Things I Regret About Node.js".^[8] In his talk, Dahl mentioned his regrets about the initial design decisions with Node.js, focusing on his choices of not using promises in API design, usage of the legacy build system GYP, node_modules and package.json, leaving out file extensions, magical module resolution with index.js and breaking the sandboxed environment of V8.^[9] He eventually presented the prototype of Deno, aiming to achieve system call bindings through message passing with serialization tools such as Protocol Buffers, and to provide command line flags for access control.

Deno was initially written in Go and used Protocol Buffers for serialization between privileged (Go, with system call access) and unprivileged (V8) sides.^[10] However, Go was soon replaced with Rust due to concerns of double runtime and garbage collection pressure.^[11] Tokio was introduced in place of libuv as the asynchronous event-driven platform,^[12] and FlatBuffers was adopted for faster, "zero-copy" serialization and deserialization^[13] but later in August 2019, FlatBuffers was removed^[14] after publishing benchmarks that measured a significant overhead of serialization in April 2019.^[15]

A standard library, modeled after Go's standard library, was created in November 2018 to provide extensive tools and utilities, partially solving Node.js' dependency tree explosion problem.^[16]

The official Deno 1.0 was released on May 13, 2020.^[17]

Deno Deploy, inspired by Cloudflare Workers,^[18] was released on June 23, 2021.^[19] Announced May 4, 2022 Beta 4 improved the dashboard and added billing functionality.^[20]

Deno Fresh 1.0 was announced June 28, 2022.^[21] It features a new full stack web framework for Deno that sends zero JavaScript to the client. The framework has no build step which allows for an order of magnitude improvements in deployment times. Version 1.1 was released September 8, 2022.^[22]

Deno SaaSKit beta was announced April 4, 2023.^[23] It is an open-source, modern SaaS template built with Fresh and Deno.

Overview

Deno aims to be a productive and secure scripting environment for the modern programmer.^[5] Similar to Node.js, Deno emphasizes event-driven architecture, providing a set of non-blocking core I/O utilities, along with their blocking versions. Deno could be used to create web servers, perform scientific computations, etc. Deno is open source software under the MIT License.^[24]

Comparison with Node.js

Deno and Node.js are both runtimes built on the V8 JavaScript engine developed by the Chromium Project, the engine used for Chromium and Google Chrome web browsers. They both have internal event loops and provide command-line interfaces for running scripts and a wide range of system utilities.

Deno mainly deviates from Node.js in the following aspects:^[5]

Supports only ES Modules like browsers where Node.js supports both ES Modules and CommonJS. CommonJS support in Deno is possible by using a compatibility layer.^[25]^[26]
Supports URLs for loading local or remote dependencies, similar to browsers, and uses module specifiers like npm: and node: to import NPM or polyfill Node.JS modules. Node.js supports both URLs^[27] and modules.
Does not require a package manager for resource fetching, thus no need for a registry like npm.^[28]
Supports TypeScript out of the box,^[29] using a snapshotted TypeScript compiler or the swc compiler^[30] with caching mechanisms.
Aims for better compatibility with browsers with a wide range of Web APIs.
Restricts file system and network access by default in order to run sandboxed code.
Supports a single API to utilize promises, ES6 and TypeScript features whereas Node.js supports both promise and callback APIs.
Minimizes core API size, while providing a large standard library with no external dependencies.
Uses message passing channels for invoking privileged system APIs and using bindings.

Funding

On March 29, 2021, Deno Land Inc was announced, with backing in millions of dollars from Shasta Ventures, Mozilla Corporation and a few others. It was established to further the development of Deno and provide a commercial offering to users.^[1]

A year on, Deno announced a further $21 million in Series A funding led by Sequoia Capital.^[31]

Release history

The tables below were created using the official Releases page.^[32]

Deno

Deno Fresh

Version numbers are based on releases from Github.^[33]

Version	Latest patch release	Release date	Date of last patch release	Description
Old version, no longer maintained: 1.0.0	Old version, no longer maintained: 1.0.0	2022-06-28	2022-06-28	Initial release
Old version, no longer maintained: 1.1.0	Old version, no longer maintained: 1.1.6	2022-08-09	2023-05-23	Automatic JSX, new twind plug-in, Preact Signals support, Preact DevTools support, explicit rendering of 404 pages, stacked middleware, experimental Deno.serve support, showcase & "Made with Fresh" badges
Old version, no longer maintained: 1.2.0	Old version, no longer maintained: 1.2.0	2023-06-15	2023-06-15	More datatypes supported in island props, support for passing JSX to islands and nesting islands, support for importing packages from npm, custom HEAD request handlers, overrides for headers and status from ctx.render, asynchronous plugin rendering, simplified testing
Old version, no longer maintained: 1.3.0	Old version, no longer maintained: 1.3.1	2023-07-18	2023-07-21	Async Route Components. adding routes and/or middlewares from plugin. 500 error template fallback, error Boundaries, export multiple islands in the same file, Fresh linting rules, support for Deno.serve
Old version, no longer maintained: 1.4.0	Old version, no longer maintained: 1.4.3	2023-08-16	2023-09-06	Faster page loads with ahead-of-time compilation, custom html, head and body tags, layouts (async layouts and async app wrapper, quicker typing with define functions
Old version, no longer maintained: 1.5.0	Old version, no longer maintained: 1.5.4	2023-10-10	2023-09-06
Current stable version: 1.6.0	Current stable version: 1.6.8	2023-12-01	2024-03-22
Legend: Old version Old version, still maintained Latest version Latest preview version Future release

Deno SaasKit

Version numbers are bases on release numbers from the Github repository.^[34]

Version	Latest patch release	Release date	Date of last patch release	Description
Old version, no longer maintained: beta	Old version, no longer maintained: beta	2023-04-04	2022-04-04	Initial release
Old version, no longer maintained: 0.1.0		2023-04-19
Old version, no longer maintained: 0.2.0		2023-05-08
Old version, no longer maintained: 0.3.0		2023-06-06
Old version, no longer maintained: 0.4.0		2023-06-20		Deno KV OAuth
Old version, no longer maintained: 0.5.0		2023-06-27
Old version, no longer maintained: 0.6.0	Old version, no longer maintained: 0.6.1	2023-08-06	2023-09-12
Current stable version: 0.7.0		2023-12-19
Legend: Old version Old version, still maintained Latest version Latest preview version Future release

Examples

A basic Hello, World! program in Deno:

console.log("Hello, World!");

Global Deno namespaces expose APIs that are not available in the browser. An implementation of the Unix cat program: [1]

/**
 * cat.ts
 */
for (const filename of Deno.args) {
  const file = await Deno.open(filename);
  await file.readable.pipeTo(Deno.stdout.writable, { preventClose: true });
}

A simple Web server: [2]

Deno.serve((req) => new Response("hello world"));

Deno automatically downloads and caches the remote standard library files when the script is run, and then compiles the code.

Similarly, it can run a standard library script (such as a file server) directly without explicitly downloading, by providing the URL as the input filename (-A turns on all permissions):

$ deno run -A https://deno.land/std/http/file_server.ts
Download https://deno.land/std/http/file_server.ts
Compile https://deno.land/std/http/file_server.ts
...
HTTP server listening on http://0.0.0.0:4500/

References

^ ^a ^b Ryan Dahl, Bert Belder (2021-03-29). "Announcing the Deno Company".
^ "Contributors, denoland/deno, Github". GitHub. Retrieved 5 July 2019.
^ "Release 2.0.2". 18 October 2024. Retrieved 21 October 2024.
^ "deno/LICENSE at main". GitHub. Retrieved 5 July 2019.
^ ^a ^b ^c ^d "Deno Manual". deno.com. Retrieved 2019-05-17.
^ Schiemann, Dylan (December 26, 2018). "Deno: Secure V8 TypeScript Runtime from Original Node.js Creator". InfoQ. Archived from the original on May 17, 2019. Retrieved May 17, 2019.
^ Paul Krill (2018-06-21). "Ryan Dahl's Node.js regrets lead to Deno". InfoWorld. Archived from the original on 2019-04-14.
^ JSConf (2018-06-06), 10 Things I Regret About Node.js - Ryan Dahl - JSConf EU 2018, retrieved 2019-05-17
^ Dahl, Ryan (2018-06-06). "Design mistakes in Node" (PDF). Github.
^ "denoland/deno, branch "golang"". Github.
^ "Suggestion: Look into porting to Rust and using Tokio". GitHub.
^ "Tokio - The asynchronous run-time for the Rust programming language". Tokio.rs.
^ "Protobuf seems like a lot of overhead for this use case?". Github.
^ "Remove flatbuffers". GitHub.
^ "Replace flatbuffers". GitHub. April 15, 2019. Retrieved July 11, 2019.
^ "denoland/deno_std: deno standard modules". Github. 3 March 2022.
^ "Deno 1.0". deno.com. Retrieved 2020-05-14.
^ Dahl, Ryan (4 May 2022). "JavaScript Containers". tinyclouds.org. Archived from the original on 4 May 2022.
^ Krill, Paul (2021-06-24). "Deno Company unveils server-side JavaScript hosting service". InfoWorld. Archived from the original on 27 Jun 2022. Retrieved 2022-04-14.
^ Krill, Paul (2022-06-03). "Deno Deploy moves toward GA, adds paid plan". InfoWorld. Retrieved 2022-07-24.
^ Luca, Casonato (2022-07-22). "Introduction Fresh 1.0 as new full stack web framework for Deno". Deno Blog. Retrieved 2022-07-24.
^ Casonato, Luca (2022-09-08). "Fresh 1.1 - automatic JSX, plugins, DevTools, and more". Deno Blog. Retrieved 2022-09-10.
^ Jiang, Andy (2023-04-04). "Announcing Deno SaaSKit: an open-source SaaS template built with Fresh". Deno Blog. Retrieved 2022-04-04.
^ "Deno Is Ready for Production". InfoQ. Retrieved 2020-07-01.
^ "Modules: ECMAScript modules | Node.js v17.6.0 Documentation".
^ "Deno - A modern runtime for JavaScript and TypeScript".
^ "Modules: ECMAScript modules | Node.js v17.6.0 Documentation".
^ "Deno - A modern runtime for JavaScript and TypeScript".
^ "Deno.js in Production. Key Takeaways". Medium.com. Retrieved 16 May 2022.
^ "Documentation". GitHub. 3 March 2022.
^ "Deno raises $21M". deno.com. Archived from the original on 22 June 2022.
^ "Releases". GitHub. 2020-12-30. Retrieved 2021-01-14.
^ "Releases".
^ "Releases".

External links

[COMPANY-1] Ryan Dahl, Bert Belder (2021-03-29). "Announcing the Deno Company".

[2] "Contributors, denoland/deno, Github". GitHub. Retrieved 5 July 2019.

[wikidata-5ad281aacde0838bb309bdf32012970f142bb446-v18-3] "Release 2.0.2". 18 October 2024. Retrieved 21 October 2024.

[4] "deno/LICENSE at main". GitHub. Retrieved 5 July 2019.

[:1-5] "Deno Manual". deno.com. Retrieved 2019-05-17.

[6] Schiemann, Dylan (December 26, 2018). "Deno: Secure V8 TypeScript Runtime from Original Node.js Creator". InfoQ. Archived from the original on May 17, 2019. Retrieved May 17, 2019.

[7] Paul Krill (2018-06-21). "Ryan Dahl's Node.js regrets lead to Deno". InfoWorld. Archived from the original on 2019-04-14.

[:0-8] JSConf (2018-06-06), 10 Things I Regret About Node.js - Ryan Dahl - JSConf EU 2018, retrieved 2019-05-17

[9] Dahl, Ryan (2018-06-06). "Design mistakes in Node" (PDF). Github.

[10] "denoland/deno, branch "golang"". Github.

[11] "Suggestion: Look into porting to Rust and using Tokio". GitHub.

[12] "Tokio - The asynchronous run-time for the Rust programming language". Tokio.rs.

[13] "Protobuf seems like a lot of overhead for this use case?". Github.

[14] "Remove flatbuffers". GitHub.

[15] "Replace flatbuffers". GitHub. April 15, 2019. Retrieved July 11, 2019.

[16] "denoland/deno_std: deno standard modules". Github. 3 March 2022.

[17] "Deno 1.0". deno.com. Retrieved 2020-05-14.

[18] Dahl, Ryan (4 May 2022). "JavaScript Containers". tinyclouds.org. Archived from the original on 4 May 2022.

[19] Krill, Paul (2021-06-24). "Deno Company unveils server-side JavaScript hosting service". InfoWorld. Archived from the original on 27 Jun 2022. Retrieved 2022-04-14.

[20] Krill, Paul (2022-06-03). "Deno Deploy moves toward GA, adds paid plan". InfoWorld. Retrieved 2022-07-24.

[:2-21] Luca, Casonato (2022-07-22). "Introduction Fresh 1.0 as new full stack web framework for Deno". Deno Blog. Retrieved 2022-07-24.

[:3-22] Casonato, Luca (2022-09-08). "Fresh 1.1 - automatic JSX, plugins, DevTools, and more". Deno Blog. Retrieved 2022-09-10.

[23] Jiang, Andy (2023-04-04). "Announcing Deno SaaSKit: an open-source SaaS template built with Fresh". Deno Blog. Retrieved 2022-04-04.

[24] "Deno Is Ready for Production". InfoQ. Retrieved 2020-07-01.

[25] "Modules: ECMAScript modules | Node.js v17.6.0 Documentation".

[26] "Deno - A modern runtime for JavaScript and TypeScript".

[27] "Modules: ECMAScript modules | Node.js v17.6.0 Documentation".

[28] "Deno - A modern runtime for JavaScript and TypeScript".

[29] "Deno.js in Production. Key Takeaways". Medium.com. Retrieved 16 May 2022.

[30] "Documentation". GitHub. 3 March 2022.

[31] "Deno raises $21M". deno.com. Archived from the original on 22 June 2022.

[releases-32] "Releases". GitHub. 2020-12-30. Retrieved 2021-01-14.

[33] "Releases".

[34] "Releases".

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@@ Line 18: / Line 18: @@
 '''Deno''' ({{IPAc-en|d|iː|n|oʊ}}<ref name=":1">{{cite web|url=https://docs.deno.com/runtime/manual|title=Deno Manual|website=deno.com|access-date=2019-05-17}}</ref>) is a [[Runtime system|runtime]] for [[JavaScript]], [[TypeScript]], and [[WebAssembly]] that is based on the [[V8 (JavaScript engine)|V8]] JavaScript engine and the [[Rust (programming language)|Rust]] programming language. Deno was co-created by [[Ryan Dahl]], who also created [[Node.js]].<ref>{{cite web |last=Schiemann |first=Dylan |date=December 26, 2018 |title=Deno: Secure V8 TypeScript Runtime from Original Node.js Creator |url=https://www.infoq.com/news/2018/12/deno-v8-typescript |url-status=live |access-date=May 17, 2019 |website=InfoQ |language=en-US |archive-date=May 17, 2019 |archive-url=https://web.archive.org/web/20190517060537/https://www.infoq.com/news/2018/12/deno-v8-typescript }}</ref>
-Deno explicitly takes on the role of both runtime and [[package manager]] within a single [[executable]], rather than requiring a separate [[Package manager|package-management program]].<ref name=":1" /><ref>{{cite web|url=https://www.infoworld.com/article/3283250/ryan-dahls-nodejs-regrets-lead-to-deno.html|archive-url=https://web.archive.org/web/20190414195245/https://www.infoworld.com/article/3283250/ryan-dahls-nodejs-regrets-lead-to-deno.html|archive-date=2019-04014|title=Ryan Dahl's Node.js regrets lead to Deno|author=Paul Krill|publisher=[[InfoWorld]]|date=2018-06-21}}</ref>
+Deno explicitly takes on the role of both runtime and [[package manager]] within a single [[executable]], rather than requiring a separate [[Package manager|package-management program]].<ref name=":1" /><ref>{{cite web|url=https://www.infoworld.com/article/3283250/ryan-dahls-nodejs-regrets-lead-to-deno.html|archive-url=https://web.archive.org/web/20190414195245/https://www.infoworld.com/article/3283250/ryan-dahls-nodejs-regrets-lead-to-deno.html|archive-date=2019-04-14|title=Ryan Dahl's Node.js regrets lead to Deno|author=Paul Krill|publisher=[[InfoWorld]]|date=2018-06-21}}</ref>
 == History ==

v t e JavaScript
Code analysis	ESLint JSHint JSLint
Supersets	JS++ TypeScript ArkTS
Transpilers	AtScript Babel ClojureScript CoffeeScript Dart Elm Emscripten Google Closure Compiler Google Web Toolkit Haxe LiveScript Morfik Nim Opa PureScript Reason WebSharper
Concepts	JavaScript library JavaScript syntax
Debuggers	Chrome DevTools Firefox Inspector Komodo IDE Microsoft Edge DevTools Opera DevTools Safari Web Inspector
Doc generators	JSDoc
Editors (comparison)	Ace Cloud9 IDE Atom CodeMirror Brackets Light Table PhpStorm Orion Visual Studio Visual Studio Express Visual Studio Code Visual Studio Team Services Vim
Engines	List of ECMAScript engines
Frameworks	Comparison of JavaScript frameworks List of JavaScript libraries
Related technologies	Ajax AssemblyScript asm.js Cascading Style Sheets Document Object Model HTML HTML5 JSON WebAssembly WebAuthn
Package managers	npm pnpm yarn
Module bundlers	Webpack Vite esbuild
Server-side	Active Server Pages Bun CommonJS Deno JSGI Node.js
Unit testing frameworks (list)	Jasmine Mocha QUnit
People	Douglas Crockford Ryan Dahl Brendan Eich John Resig