DuckDuckGo Zero-click Info includes topic summaries, categories, disambiguation, official sites, !bang redirects, definitions and more. You can use this API for many things, e.g. define people, places, things, words and concepts; provides direct links to other services (via !bang syntax); list related topics; and gives official sites when available.

The PubNub Network makes Real-time Communications Simple with an easy API. Two Functions: Send/Receive (Publish/Subscribe). We provide a web-scale API for businesses to build scalable Data Push communication apps on Mobile, Tablet and Web. Bidirectional JSON. Ask for commit access - via Twitter: @pubnub - via IRC: #pubnub on FreeNode

UP is a wristband and app that tracks how you sleep, move and eat—then helps you use that information to feel your best. The UP Platform documentation provides information related to establishing and maintaining an API connection with UP. The purpose of this API is to enable the exchange of select data in order to extend and augment the UP user experience and support complementary services. This can include data aggregation and visualization, gaming, marketing, rewards provisioning, and more.

Imgur's API exposes the entire Imgur infrastructure via a standardized programmatic interface. Using Imgur's API, you can do just about anything you can do on imgur.com, while using your programming language of choice. If you're familiar with the APIs of Twitter, Amazon's S3, del.icio.us, or a host of other web services, you'll feel right at home. The full documentation is available at: http://api.imgur.com

Indeed is the #1 job site worldwide, with over 100 million unique visitors per month. Indeed is available in more than 50 countries and 26 languages, covering 94% of global GDP.

Words API lets you retrieve information about English words, including definitions, synonyms, rhymes, pronunciation, syllables, and frequency of usage. It also can tell you about relationships between words, for instance that "math" has categories like "algebra" and "geometry", or that a "finger" is part of a "hand".

Retrieve or update Twitch content via REST API. 50char

CloudSight API (fka CamFind API) is the image recognition and reverse image search that powers the popular mobile visual search engine app, CamFind. It is the welcomed replacement for the void left following the purchase of IQ Engines by Yahoo!. CloudSight API promises to be the best solution for state of the art image recognition and reverse image recognition, which developers can incorporate into both apps and web applications.