80legs

80legs is a service platform for web crawling and processing web content. The 80legs API gives developers a simple programmatic interface with access the functionality that 80legs provides outside of the web portal. This is a fee based service.

Safe Creative

Safe Creative is an on-line world wide copyright registry, free and open to use. It allows creators/rightholders to register their works. The service supports many license types: traditional copyright, Creative Commons, custom, etc.
Safe Creative

oDesk

oDesk is a marketplace for online workteams, with a unique business model for both buyers and providers that looks to guarantee to buyers that an hour billed is an hour worked, while guaranteeing to providers that an hour worked is an hour paid. The oDesk public API allows developers to access the oDesk platform from outside oDesk.com, search jobs and providers and view detailed work histories of others on your team. Also check your messages and reply to important messages via the API.
oDesk

Playme

The Play.me API helps developers to plug into nearly 6 million* song catalog and create new and innovative web, mobile and desktop widgets and applications allowing music fans to do even more with the music they love (album, artists, playlists, radio, stream, download and more). there are different integration level, non commercial, affiliate program and partnership. *Depending on territory.
Playme

Facebook Ads

Provides methods to add, edit and manage advertising campaigns running within Facebook. Your ad management application can work with keywords, ad groups and even generate reports.
Facebook Ads

Factual

Factual is an open data platform for application developers that leverages large-scale data aggregation and community exchange. Our focus is on making data more accessible (i.e. cheaper, higher quality, less encumbered) for machines and developers, to drive and accelerate innovation in an unprecedented way. We take on the dirty work of data management and data curation, letting developers focus on higher value and more productive tasks. We provide clean, structured data with complete source transparency to developers via both download and API access on liberal terms.
Factual

TownMe Geo

The TownMe API, at GeoAPI.com, has now been fully incorporated into Twitter's services. Before the acquisition, it included both read and write geo-related services. The read side had a reverse geocoder which helped translate coordinates (AKA lat/longs) into human readable elements or associations. For instance, give the API "37.78093,-122.409415" and it returned information about the census tract, neighborhood, city, MSA, and state that contains these coordinates. The POI Finder took a lat long and gave a set of points of interests including businesses close to that point. This meant anyone could build services that allowed users to broadcast location or otherwise interact with their "real location". The write components of the API included: The ability to write data about locations. Each API key came with its own overlay of the world and the ability to write data to this overlay. So, if you were writing an augmented reality game and wanted to hide a ghost at a bar in San Francisco, you could write the ghost to the bar using the API and all your users would find it there. This information was be stored on TownMe servers, which means all these interactions could be written in JavaScript without requiring server code.
TownMe Geo

Yahoo Contacts

The Yahoo Contacts API enables applications to view and edit the social relationships that exist in the Yahoo Address Book. The Contacts API is based on OAuth, which allows the secure transfer of data in a way that respects user privacy and permissions.
Yahoo Contacts

Rhyming

An HTML scraper of rhymezone. Users can enter words and rhyming words are returned. Formats range from JSON, XML, and an HTML table. No sign-up requirements or developer keys required. Get the rhyme you are looking for.
Rhyming

Yebol

Yebol is a new semantic search engine that currently has 10 million search terms and growing. From the website: " Yebol allows for a multi-dimensional search result instead of the normal one-dimensional search seen by most web search engines today. This provides a more accurate summary of top sites and categories; a wider array of related search terms; a longer and richer expansion for query results; and a deeper base of links and keywords in search result pages."
Yebol