Chris Lattner, the creator of and project lead for Apple’s Swift programming language, today announced in a mailing list email that he will be leaving Apple later this month. He will be joining Tesla as the car company’s vice president of Autopilot autonomous driving software, Tesla said in a blog post.

Lattner has been at Apple since 2005 and is currently senior director of the company’s development tools department, which works on, among other things, Swift, the Swift Playgrounds iPad app that teaches Swift, and the Xcode integrated development environment (IDE) inside of which developers can use Swift. He’ll be passing on the project lead role to his colleague Ted Kremenek, Apple’s senior manager of languages and runtimes.

Lattner is leaving in order to “pursue an opportunity in another space,” he wrote in the email. Although he won’t be inside the company going forward, Swift is after all an open-source project, unlike its predecessor, Objective-C, and as such Lattner will be able to and in fact will keep participating, specifically as a member of the Swift core team, he wrote in the email.

Still, the company is losing a key figure who has headed up the company’s most prominent open-source project in recent memory. Swift is the 24th most popular project on GitHub based on number of stars.

Apple first introduced Swift in 2014 and open-sourced it in late 2015. With Swift, developers can build iOS, macOS (formerly OS X), tvOS, and watchOS apps.

Lattner first started working on Swift in 2010.

“I implemented much of the basic language structure, with only a few people knowing of its existence. A few other (amazing) people started contributing in earnest late in 2011, and it became a major focus for the Apple Developer Tools group in July 2013,” he wrote on his website.

Swift Playgrounds became available on the App Store in September.

“I hope that by making programming more approachable and fun, we’ll appeal to the next generation of programmers and to help redefine how Computer Science is taught,” he says on his website. “Swift Playgrounds for the iPad is a crucial piece of this: it uses real Swift code to teach programming fundamentals, while also providing a full featured native iOS development experience that allows access to almost the entire iOS SDK. Swift Playgrounds includes high production value assets and curriculum produced by Apple, which provides a appealing and safe introduction to programming concepts for everyone.”

Before arriving at Apple, while at University of Illinois Urbana-Champaign, Lattner started the Low Level Virtual Machine (LLVM), which is now part of the wider LLVM umbrella project that contains compilers and other software development tools. In 2012 Lattner, along with Vikram Adve and Evan Cheng, received the prominent ACM Software System Award for LLVM.

Update at 2:01 p.m. Pacific: Added information about what Lattner will do next.