ReadWriteWeb

Message Bus is a new company that will offer an API for sending e-mail. It sounds like SendGrid or Amazon SES (see our coverage of SES for more competitors in this area). According to the blog post announcing the project, the team is focusing on an agnostic messaging architecture, "at the plumbing level, Twitter's road not taken."

Message Bus was founded by CTO Jeremy LaTrasse, former operations manager at Twitter and President Narendra Rocherolle and CEO Nick Wilder, both formerly of Webshots and 30Box.

rStat.us is an OStatus-based microblogging service built by Steve Klabnik and others using Ruby, Sinatra and MongoDB. Because it uses OStatus, it's compatible with Identi.ca and StatusNet microblogs. In order to follow someone from Identi.ca, just paste the ATOM feed from their profile into rStat.us. Theoretically this should work both ways, but I was unable to subscribe to my own rStat.us account from Identi.ca account.

Klabnik and some friends started it after Twitter changed its terms of service and began discouraging developers to start new Twitter clients.

The Data Science Toolkit is a collection of data tools and open APIs curated by our own Pete Warden. You can use it to extract text from a document, learn the political leanings of a particular neighborhood, find all the names of people mentioned in a text and more. He unveiled it today at GigaOM Structure in San Francisco GigaOM Structure Big Data in New York City.

It's available as a Web service, or you download a virtual machine and host it on your own server.

Context.IO is an API for email, giving developers the ability to use email as a platform. Context.IO aims to replace complex sequences of IMAP requests with simple API calls.

The first 100 readers to sign-up using the code RWW100 will be admitted to the private beta. The API will be opened to more developers next month.

Today Google announced support for the OAuth 2.0 protocol, although the standard isn't yet complete. Version 2.0 is designed for developer simplicity. Developers frequently complain about the difficulty of using OAuth to integrate applications with Google Apps.

Google also introduced a new OAuth consent page that it hopes will be simpler to understand.

Streaming music subscription service Rdio today announced availability of a series of Application Programming Interfaces (APIs) that outside developers can use to add playback of Rdio's 8 million song catalog and social features like popular playlists to their web applications.

Developers that can sign up new subscribers to Rdio's $5 or $10 per month paid services will receive a 2% to 3% commission for the lifetime of the subscriber. That could help create a small army of sales people that could sell Rdio in settings outside of the Rdio iPhone app, where Apple will soon begin taking a hefty 30% cut.

Instead of a single API, this week we're highlighting Mashery's new API discovery hub. The hub indexes APIs ranging from the The Guardian Open Platform to the Cheezburger Developer Network.

And if you build something cool with one of those APIs, be sure to submit it to the new applications directory showcasing apps built by developers using Mashery-powered APIs.

Today Google announced the Google APIs Explorer, a Web-based interface for experimenting with the company's various APIs. So far only seven APIs are supported, Google the company promises to add more soon.

The Explorer lets you select a supported service and view a list of supported methods. You can then select a method, fill in the parameters, execute the command and get the results. It seems like a great way to try out an API without writing code. Google's announcement has a few sample requests to get started with.

Yesterday Google launched AdWords API v201101. The new addresses requests for faster reports, adds the ability to run experimental ad campaigns and expands support for geo-targeted ad campaigns.

Google will deprecate old versions of the API August 2011.

Last week SlideShare announced its new JavaScript API for controlling embedded players. The company also added support for the oEmbed API.

The new JavaScript API gives developers the ability to: "access major functions, navigate across presentations, and control the SlideShare embed player via Javascript." What can you do with those features? SlideShare suggests that you could use it to automate multiple players to show random slides one at a time or synchronize slides and video. I'm sure you can find more creative uses, though.