Justin Spahr-Summers


I’m a Cocoa and Cocoa Touch developer based out of San Francisco, with a deep interest in open source and functional programming.

I’ve created or helped create several popular open source projects, including:

  • ReactiveCocoa, a framework for functional reactive programming in Cocoa
  • Carthage, a simple, decentralized dependency manager for Cocoa projects
  • Mantle, a model framework for Objective-C that greatly reduces boilerplate
  • libextobjc, a library to extend the Objective-C programming language

… as well as some niche projects, like:

I’ve given a few talks as well:

To see more of what I’ve done, check out my GitHub profile. I’ve also occasionally written answers on Quora and Stack Overflow.

If you’re interested in sponsoring any of these projects, please get in touch!

I’m also enormously grateful for any donations to support my open source work, via Patreon or Gratipay.