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Objective-C: How Brad Cox’s programming language has shaped Sketch since day one

After the passing of Objective-C’s creator, we reflect on how instrumental it has been for our company and our industry

We often use this blog to talk about new Sketch features, or pull back the curtain on how we work here — such as exploring our creative process, or looking into how we optimize the Mac app. But one thing I don’t think we’ve ever really talked about is our programming language.

Today, though, as we reflect on the recent passing of Objective-C’s co-creator Dr Brad Cox Ph.D., we have a good reason to do just that.

Objective-C was first adopted by NeXT, and later became the foundation of Mac OS X (now known as macOS). It was the best way to write Mac apps — and for the first eight years or so of Sketch, we wrote almost all the app’s code with it. Most of that code is still there.

A programming language really forms the lowest building blocks of an app, and shapes how developers interact with the machine. It has a foundational impact on what’s possible, and therefore directly affects the final product — far more than an end-user could ever know.

Dr Cox and his business partner, Tom Love, built Objective-C on top of the old industry foundation of C, and the result was a powerful and very dynamic language. Its infamous quirk — the ‘weird’ square-bracket syntax it used for its functions — puzzled many an early developer. But once you got past that, you got the high speed and low memory footprint of regular C code, with a thin but flexible Object-Oriented layer on top.

It was certainly a big step up from Java and Swing, which I learnt at University. I would simply describe it as ‘elegant’ — something I’d never say of those two languages. Despite the Mac’s small market share at the time, that elegance got me hooked. I was instilled with a desire to create apps that were like Apple’s — and like those made by the other indies out there that I respected tremendously.

The influence of Objective-C can hardly be understated. I think it’s fair to say that there would’ve been no iPhone without Objective-C. It’s certainly true that AppKit — NeXT’s and later Apple’s original UI framework — was built for Objective-C. The language and the frameworks were beautiful, and a joy to work with. They’re a bit long in the tooth now, but they’re still going strong more than 30 years on, and that is in no small part thanks to the language they were all built on. That’s one hell of a legacy to leave behind, and we at Sketch are eternally grateful for it.

If you want to read more about Objective-C’s origins, check out Masterminds of Programming by Federico Biancuzzi, or take some time to read John Gruber’s recent musings on its impact.