The Developer Who Quietly Saved JavaScript

The Most Influential JavaScript Developer You've Never Heard Of

If you ask most developers to name the people who shaped modern JavaScript, you'll get a predictable list: Brendan Eich for creating it, Ryan Dahl for taking it server-side with Node.js, and maybe Douglas Crockford for at least trying to explain why it wasn't a complete disaster. But there's one name that almost never comes up — Jeremy Ashkenas — despite the fact that the JavaScript you write every single day is built on foundations he laid between 2009 and 2012.

This isn't a nostalgic tribute for its own sake. Understanding what Ashkenas did, and why he did it, tells you something genuinely useful about how programming languages evolve, how developer tooling compounds over time, and why the "best" solution in any given moment is usually just the least-bad option that someone had the courage to ship.

What JavaScript Actually Looked Like in 2009

To appreciate what Ashkenas fixed, you need a clear picture of what he was working with. JavaScript in 2009 was a genuinely hostile environment for serious application development. There were no classes — inheritance meant manually manipulating a prototype chain that most developers didn't fully understand and nobody really wanted to touch. Variable scoping was handled exclusively through var, which hoisted declarations to the top of function scope in ways that produced subtle, infuriating bugs. There was no destructuring, no arrow functions, no template literals, and no spread operator.

Browser inconsistency made it worse. Firefox had shipped array helper methods like map, reduce, and forEach. Internet Explorer had not. That meant you either polyfilled everything yourself or went without, and in practice most teams went without and wrote loops by hand. Writing a moderately complex application in JavaScript meant accepting that your code would be verbose, fragile, and thoroughly untested — not because developers were lazy, but because the language gave them almost nothing to work with.

The dominant approach to managing this chaos was jQuery, which smoothed over browser inconsistencies for DOM manipulation but didn't solve the deeper structural problems. Your data, your event handlers, and your DOM updates all lived in the same tangled file, and scaling that approach to thousands of lines was a reliable path to a codebase no one wanted to maintain.

Underscore.js: Giving JavaScript a Standard Library

Ashkenas's first major contribution was Underscore.js, released in 2009. At its core, Underscore was a utility belt — roughly 60 helper functions for working with arrays, objects, and functions. Things like _.map(), _.filter(), _.reduce(), _.debounce(), and _.template(). By today's standards, that sounds like a modest weekend project. In 2009, it was a lifeline.

What Underscore demonstrated was a repeatable pattern in software development: when a language lacks something that developers need, someone will build it, people will adopt it, and eventually the language will absorb it. That's exactly what happened. ECMAScript 5 and later ES6+ incorporated most of what Underscore offered natively. The library effectively became a proposal for what JavaScript's standard library should look like, written in shipping code rather than a committee document.

Lodash, a more performance-optimised fork of Underscore, continued that legacy and still sits among the most downloaded npm packages today. The direct lineage from Underscore to native Array.prototype methods is one of the cleaner examples of open source shaping language design.

CoffeeScript: Compiling Your Way to a Better Language

Underscore was pragmatic. CoffeeScript was ambitious. Released in 2010, it was a language that compiled to JavaScript — which meant Ashkenas could fix the syntax without waiting for browser vendors or the TC39 standards committee to agree on anything.

CoffeeScript stripped out the function keyword in favour of lightweight arrow-style syntax, added classes with clean inheritance, introduced string interpolation, made significant whitespace meaningful (borrowing from Python), and cleaned up conditionals and loops into something that actually read like code a human being might write intentionally. You wrote CoffeeScript; the compiler produced valid JavaScript that ran everywhere.

It worked. DHH adopted it almost immediately, and Rails 3.1 shipped with CoffeeScript as the default JavaScript preprocessor in 2011. GitHub, Dropbox, and a significant slice of the early 2010s startup ecosystem built their front ends in CoffeeScript. For a period of two to three years, it was the credible answer to the question of how to take JavaScript seriously.

CoffeeScript is essentially defunct now, and for good reason — Babel and the ES6+ specification delivered most of what it promised directly in the language itself. Classes, arrow functions, template literals, default parameters, destructuring, the spread operator — all of these features have CoffeeScript's fingerprints on them. The language won by being absorbed, which is a strange kind of victory but a real one.

The deeper lesson here is about the strategic value of compile-to-JS languages as a pressure mechanism. TypeScript followed the same model and has had an even more profound influence on JavaScript's direction, particularly around type-aware tooling. Ashkenas proved the approach was viable before TypeScript existed.

Backbone.js: The First Architecture for the Front End

By 2010, JavaScript had a workable utility library and a cleaner syntax option. What it still lacked was any coherent way to structure a large client-side application. Ashkenas's answer was Backbone.js — fewer than 2,000 lines of code that introduced MVC concepts to the front end in a way developers could actually use.

Backbone gave you Models to hold your data, Collections to group models, Views to handle rendering and user interaction, and a lightweight event system to keep everything synchronised. It was deliberately minimal. Backbone didn't tell you how to organise your files or prescribe a build system — it gave you the primitives and trusted you to compose them into something coherent.

The results were significant. Backbone powered early versions of Trello, Airbnb, Hulu, and Pinterest. It demonstrated something that wasn't obvious at the time: you could build genuinely complex, production-grade applications in client-side JavaScript without the whole thing collapsing under its own weight. That proof of concept mattered enormously, because it shifted the industry's assumptions about what the browser was capable of handling.

Angular arrived in 2010, Ember in 2011, and React in 2013. Each pushed further than Backbone did, introducing two-way data binding, component models, and virtual DOM diffing. Backbone became obsolete in roughly the same way that Underscore and CoffeeScript did — by being surpassed by tools it had inspired. But without Backbone establishing that client-side MVC was a solvable problem worth solving, it's genuinely unclear whether the investment in those later frameworks would have happened at the same pace.

The Pattern Behind the Contributions

Looked at individually, Underscore, CoffeeScript, and Backbone.js are three separate tools in three different categories. Looked at together, they represent a coherent diagnosis of what was broken in JavaScript development circa 2009 and a systematic attempt to fix each problem in sequence.

First, the missing standard library. Then, the hostile syntax. Then, the lack of application architecture. Each solution was practical rather than perfect, minimal rather than overengineered, and influential enough to pull the wider ecosystem forward. That's a rare combination. Most developers who identify a problem in a language either contribute a proposal to a standards body or tweet about it. Ashkenas shipped three category-defining tools in three years.

There's also something worth noting about the obsolescence pattern. All three tools were eventually made redundant by the improvements they inspired. That's not failure — that's exactly how healthy ecosystems evolve. The goal was never to own the JavaScript toolchain permanently; it was to move the language and the community forward. By that measure, the contributions were extraordinarily successful.

Why This History Still Matters for Working Developers

Knowing this history isn't just trivia. It has practical implications for how you evaluate tools and make architectural decisions today.

When you reach for a library, it's worth asking whether you're solving a genuine language gap or compensating for a skill gap. Underscore was solving a real gap. Many npm packages today are solving skill gaps — they exist because developers don't want to learn the underlying API, not because the API is genuinely insufficient. Those are different problems with different solutions.

When you see a compile-to-JS language gain traction — TypeScript being the obvious current example — the CoffeeScript story tells you it's worth taking seriously, even if the syntax looks unfamiliar. Languages that compile to JavaScript have a proven track record of pulling JavaScript itself forward.

And when you're building something with a new framework, the Backbone story is a useful reminder that minimal, composable tools often prove more durable than opinionated, comprehensive ones. React's component model is significantly more constrained than Backbone's free-form approach, but the underlying instinct — give developers primitives they can compose — is the same.

Jeremy Ashkenas didn't save JavaScript by writing something permanent. He saved it by writing things that were good enough to become unnecessary. That's a harder achievement than it sounds, and it's worth remembering who pulled it off.

Frequently Asked Questions

Who is Jeremy Ashkenas and why is he significant?

Jeremy Ashkenas is a software developer best known for creating three highly influential JavaScript tools: Underscore.js, CoffeeScript, and Backbone.js. Each was released between 2009 and 2010, during a period when JavaScript was widely regarded as a poor choice for serious application development. His contributions helped establish patterns and features that were later absorbed into JavaScript itself and into modern front-end frameworks.

Is CoffeeScript still used in 2024?

CoffeeScript sees very little active use today. The features that made it attractive — arrow functions, classes, string interpolation, destructuring, and the spread operator — were all incorporated into ES6 and later versions of JavaScript. Some legacy codebases, particularly older Rails applications, may still contain CoffeeScript, but new projects almost universally use TypeScript or plain JavaScript instead.

What did Backbone.js contribute to modern front-end development?

Backbone.js introduced MVC (Model-View-Collection) architecture to client-side JavaScript development at a time when there was no established pattern for structuring large front-end applications. It proved that complex, production-grade apps could be built entirely in the browser. Frameworks like Angular, Ember, and React built on the conceptual foundation Backbone established, even as they made it obsolete through more sophisticated approaches to data binding and rendering.

Why do programming libraries become obsolete after becoming popular?

This is a well-documented pattern in software ecosystems. When a library solves a problem well enough to gain widespread adoption, it signals to language designers and standards bodies that the problem is real and worth solving at the language level. Features get incorporated natively, which eliminates the performance overhead and dependency cost of the library. Underscore's utility functions, CoffeeScript's syntax improvements, and Backbone's architectural primitives all followed this trajectory — each was popular enough to influence JavaScript directly, and each was eventually superseded by the improvements it inspired.