APIs

Active Campaign - Messaging

HipChat - Messaging

Zendesk - Enterprise

AgileZen - Tools

Recurly - Financial

Dwolla - Financial

Close.io - Search

TaskRabbit - Tools

Freckle - Tools

Buffer - Social

Yammer - Enterprise

Balanced Payments - Financial

Box - Storage

Asana - Search

JSON API - Backend

StockTwits - Financial

Last.fm - Music

JavaSE6 - Enterprise

JavaSE7 - Enterprise

JavaFX - Enterprise

Fitbit - Health

Groupon - Shopping

Google Analytics - Tools

We the People API - Messaging

Pinboard - Tools

bitly - Search

Bitbucket - Search

LinkedIn - Social

Foursquare Core API - Maps

Stack Exchange - Tools