Users use many different services on the web to handle their day to day tasks, such as sharing images, editing documents and listening to music. They expect their applications to be connected and to work together seamlessly.

It is impossible for developers to anticipate every new service and to integrate with every existing external service that their users prefer, and thus they must choose to integrate with a few select APIs at great expense to the developer.

Web Intents solves this. Web Intents is a framework for client-side service discovery and inter-application communication. Services register their intention to be able to handle an action on the user's behalf. Applications request to start an Action of a certain verb (share, edit, view, pick etc.) and the system will find the appropriate Services for the user to use based on the user's preference.

Web Intents puts the user in control of service integrations and makes the developer's life simple.

Swagger is a specification and complete framework implementation for describing, producing, consuming, and visualizing RESTful web services.

The Echo Nest offers an incredible array of music data and services for developers to build amazing apps and experiences. Here is where you learn all about the features and capabilities of our platform, review tutorials and sample code, and see what tools and libraries are available. Feel free to browse around, or just dive right in by requesting an API key.

rails-api is a plugin developed by Yehuda Katz, José Valim, Carlos Antonio da Silva and me (Santiago Pastorino) which modifies Rails applications trimming down usually unneeded Rails functionalities for API applications.

Makes creating XML/JSON responses in Rails 3 easy and fun.

APIConnect is a Javascript class that provides a simplified interface (I know, that's redundant) for client-side interaction with APIs, especially those hosted on other domains. Setup is as simple as creating the instance, specifying the domain, connecting the route, and running it. APIConnect works in all major browsers and requires jQuery.

The Open Source Exchange Rates API project was designed to address a glaring problem with exchange rate data on the internet: there's an untold number of free currency conversion services, but no free/reliable place for developers to access the rates that power them.

TomDoc is a code documentation specification that helps you write precise documentation that is nice to read in plain text, yet structured enough to be automatically extracted and processed by a machine.

RoboWhois is a cloud-based web service that provides a RESTful API to access WHOIS records and domain related information with a unified, consistent interface.

Is a cron service with an api

Mapstraction is a library that provides a common API for various javascript mapping APIs to enable switching from one to another as smoothly as possible. Developers can code their applications once, and then easily switch mapping provider based on project needs, terms and conditions, and new functionality.

CarQuery is a simple to use JSON based API for retrieving detailed car information, including year, make, model, trim, and specifications.

Stripe makes it easy to start accepting credit cards on the web today.

Do you have a blog made out of static pages? Do you want to add search to it? Look no further and let Tapir handle it! Enter your feed url and you'll get a token you can use with our API to easily get search on your blog.

With REST APis

Browsers should come with APIs to parse semantic content such as microformats, unfortunately this has yet to happen. The microformat shiv provides a simple to use, light-weight, cross-browser microformat API. It even works with modern mobile browsers and is backward compatible with Internet Explore 6.

How to Use API V3 to Customize, Enhance, and Beautify your Google Map Mashups

The Like button lets a user share your content with friends on Facebook. When the user clicks the Like button on your site, a story appears in the user's friends' News Feed with a link back to your website.

Postmark helps deliver and track transactional emails for web applications. In a nutshell, the service replaces SMTP (or sendmail) with a far more reliable, scalable and care-free environment. In addition, you can track statistics for number of emails sent, bounces and spam complaints.

An API that abstracts the differences between clouds

jTweetsAnywhere is a jQuery Twitter Widget that simplifies the integration of Twitter services into your site.

The jQuery special events API is a fairly flexible system by which you can specify bind and unbind hooks as well as default actions for custom events. In using this API, you can create custom events that do more than just execute bound event handlers when triggered—these “special” events can modify the event object passed to event handlers, trigger other entirely different events, or execute complex setup and teardown code when event handlers are bound to or unbound from elements.

I knew going into it that I wanted to allow for API versioning. I didn't know much about who would be using the service, or what use cases may arise after it was launched, and versioning seemed like the best mechanism to provide our partners with a migration path should big changes need to be made. I remember trying to find a good solution to handle that, but not finding much on the topic at the time. Ultimately, I settled on a solution that was already baked right into Rails: namespaces.

There’s a lot of hot air circulating online re versioning HTTP APIs. I ignore most of it: It’s RESTy folks without real load or customers, wanking about purity.

I actually agree with some of the purist noise from a theoretical perspective, but in practice the implementations are annoying enough that they’re simply not worth the effort.

These suggestions apply to external APIs: If you control all the endpoints, or if you’re running a service where folks are more accepting of rapid change, you don’t need to worry nearly as much.

These also apply only to systems where there are lots of clients and a single service endpoint. The landscape changes a bit if clients are hitting multiple, independent installations of your service.

PostageApp is a service that fits between your web app and your email server to make email management easy by adding a level of reporting, control, and accountability.

Tropo is cloud-based communications. Using our simple API you can quickly create and deploy powerful communications applications in Groovy, JavaScript, PHP, Python, and Ruby. Tropo is powered by Voxeo - the largest and most reliable hosted communications platform in the world.

Twilio provides a web-service API for businesses to build scalable, reliable communications apps that make and receive phone calls

Free Analytics and Protection for APIs and Mashups

jQuery, since 1.2.2, has had an API for “special events”. These events are special because they have the ability to do some extra work for specific events and even the option to bypass some of the internal jQuery event system. With these special events you can create custom events that require some setup work or you can completely overwrite the behavior of native events.

OAuth allows the user to securely share data from provider sites (in this case google) to consumer sites (in this case your ruby on rails site). You can use OAuth to authenticate users or consume API’s on their behalf. Here we will have a look at both.

Yahoo! Placemaker is a freely available geoparsing Web service. It helps developers make their applications location-aware by identifying places in unstructured and atomic content – feeds, web pages, news, status updates – and returning geographic metadata for geographic indexing and markup.

Twibot 0.1.1 hit the RubyForge gem server today. Inside is a microframework for writing Twitter bots in Ruby, using a DSL heavily inspired by Sinatra.

Allow your players to share strategies and tips and friend each other in real time
Create a multi-player community feel even in a single player game
Communicate with your player base instantly without updating the application
Monitor what your users are saying all the time, no matter where you are
Expose your games to a broader audience in community chat rooms

After publishing the Ruby on Rails dictionary for Mac OS X, i got huge number of request to do the very same with Ruby API documentation. Fortunately, most of the work has already been done and now it's time to publish the Ruby dictionary generated from Ruby API documentation.

Create HTML POST forms that allow your web site visitors to upload files into your S3 account using a standard web browser.

The AJAX Libraries API is a content distribution network and loading architecture for the most popular open source JavaScript libraries.

What you can and can’t do with Google Charts

Mapstraction is a library that provides a common API for various javascript mapping APIs to enable switching from one to another as smoothly as possible.

In this episode you will learn how to use campaign monitor gem to integrate your Rails app to Campaign Monitor Web Service API. I will point out the blockers that I faced during the development.

ActiveYoutube is a gem to access YouTube API using ActiveResource.

The Yahoo! Internet Location Platform provides a resource for managing all geo-permanent named places on Earth.

oEmbed is a format for allowing an embedded representation of a URL on third party sites. The simple API allows a website to display embedded content (such as photos or videos) when a user posts a link to that resource, without having to parse the resourc

A wrapper class to access the Campaign Monitor API. Written using the wonderful Flickr interface by Scott Raymond as a guide on how to access remote web services

The Google Contacts Data API allows client applications to view and update Contacts content in the form of Google Data API feeds. Your client application can request a list of a user's contacts, edit or delete content in an existing contact, and query the

Full Facebook platform support for Rails including Model, View and Controller

Jester is a JavaScript client for REST APIs that use Rails conventions, and is inspired by Rails’ own ActiveResource

A Ruby Library for Amazon's Simple Storage Service's (S3) REST API.

An insanely easy Ruby interface to the Flickr photo-sharing service.

FBJS is Facebook's solution for developers who want to use Javascript in their Facebook applications. We built FBJS to empower developers with all the functionality they need, and to protect our users' privacy at the same time.

Exhaustive list.

The Digg Application Programming Interface (API) has been created to let users and partners interact programmatically with Digg.

Wonderful!