WordPress Packagist is a service I developed at Outlandish. It provides a mirror of the WordPress plugin and theme directories as a Composer repository.
In the year since we announced it, it's seen a steady growth in usage and has been covered by several big players in the web world including Smashing Magazine and Roots.io. There's even a small community of developers on GitHub contributing enhancements and managing the support queries that come in.
There's still a long way to go in making WordPress more friendly to modern workflows and tools such as Composer. But it's great to feel that I had some small part in moving things forward.