Cool Runtimes: Deno and Bun


The JavaScript Runtime Engine ecosystem is expanding with the induction of Deno and Oven, two startups building an innovative runtime and toolset. The best part of this story is the ongoing debate among developers, which started when Oven claimed their product Bun was 3x-5x faster than Deno.

Company: Deno Land Inc.
Founded: 2019
HQ: San Diego
# of Employees: 20-30
Raised: $26M
Founders: Ryan Dahl and Bert Belder 
Product: Deno Runtime        
GitHub Stars: 85.2k
Language: Written in Rust
Founded: 2021
HQ: San Francisco
# of Employees: <10
Raised: $7M
Founders: Jarred Sumner
Product: Bun Runtime           
GitHub Stars: 33.7k
Language: Written in Zig

It seems like history is repeating itself. Last year Cloudflare claimed Workers was 196% faster than Fastly on TTFB, based on a Catchpoint test. Fastly responded forcefully a couple of weeks later. It was the first time CDNs called each other out in public. Why Cloudflare published this piece is interesting since they know Catchpoint tests are prone to manipulation.

The team behind Bun claims it is fast because it invested a lot of time in profiling, benchmarking, and optimizing the engine. Also playing in their favor is the use of Zig, a lower-level programming language created by Andrew Kelley, which he claims is as fast as C++ and faster than Rust. That’s another story.

Deno Runtime

Deno, founded by Ryan Dahl and Bert Belder, is shaking up the JRE market. Ryan is the founder of Node.js, the widely used open-source JavaScript runtime built on V8. In a recent Stack Overflow survey, Deno was more popular than Go, Rust, Ruby, and TypeScript. In addition, npm, the world’s largest software registry, is the default Package Manager for Node, extending its features and capabilities. However, Node.js is not without its issues.

Node.js is not only slow, but it lacks interoperability. The problems are so profound that Ryan decided to build what he hopes will be a replacement for Node.js. Deno is the next-generation runtime that addresses those issues. One author stated that Deno lacks significant adoption because it doesn’t work with Node modules. However, that’s changed as the Deno team works on making npm packages work with the product.

Deno has 85.2k Github stars, right behind Kubernetes and Node. That’s an impressive accomplishment. Oven’s claims have been heard loud and clear by the Deno team. Today, they are working on an HTTP server to make its runtime faster.

Bun Runtime

Oven, the company behind Bun, was founded by Jarred Sumner, a high school dropout and ex-Stripe engineer who spent more than a year building Bun solo. There is minimal data on the company itself apart from raising $7M from Kleiner Perkins and YCombinator.

Oven plans on offering hosted solutions similar to Deno. However, they plan to deploy it globally in different data centers on their hardware. In addition, Jarred noted that he intends to make Bun an end-to-end solution for JavaScript.

  • Bun is a bundler, transpiler, and package manager with npm client-built in
  • Implements hundreds of Web and Node.js APIs
  • Plans on providing serverless hosting
  • Support popular front-end and backend frameworks
  • Will eventually Run dedicated servers at the edge globally

JRE Ecosystem

JavaScript engines have been around for a while, Google developed V8 in 2008, and the browser community announced WebAssebly (Wasm) in 2015, supported in all four major browsers.

WebAssembly is a compiler that runs at native speed, is memory-safe, and operates in a sandboxed environment. It runs inside JVM (JavaScript VMs). The industry believes it is the future of web applications, making it possible to build and run compute-heavy applications in the browser, such as gaming, virtual reality, video encoding, etc. We agree with them.

There are several open-source engines in the marketplace. The most popular ones are the following:

We look forward to the impact Deno and Bun, both innovative companies, will make in the CDN industry.

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