Quoted: This page describes Rison, a data serialization format optimized for compactness in URIs. Rison is a slight variation of JSON that looks vastly superior after URI encoding. Rison still expresses exactly the same set of data structures as JSON, so data can be translated back and forth without loss or guesswork.

Facebook Posted Items API.

Quoted: Lets a user post a link on their Wall through your application. Before your application can post a link to a user's profile, the user must grant your application the share_item extended permission.

Google gadgets spec.

Quoted: The canonical gadget spec XSD contains the subset of attributes that must be parsed and interpreted by the server. In other words, the parser MUST NOT reject gadget specs conforming to the extended spec, yet need not interpret more than the canonical spec.

XSD: http://opensocial-resources.googlecode.com/svn/spec/0.8/gadgets/gadgets.xsd

Quoted: Much has been written lately about the rise of the API. Offering a programming interface to an online service is now standard practice amongst this generation of web companies. Through APIs, we get to enjoy a range of innovative Twitter clients, wideavailability of maps and location information, custom search engines, and more.

Could be useful.

Quoted: The JSON Viewer package is a set of 3 viewers available in the following flavors:
1. A standalone viewer - JsonView.exe
2. A plugin for Fiddler 2 (http://www.fiddler2.com/) - FiddlerJsonViewer.dll
3. A visualizer for Visual Studio 2005 - JsonVisualizer.dll

Just noticed the .NET 3.5 framework contains classes for emitting Atom and RSS for you. Presumably the emitted content validates.

Quoted: Represents a top-level feed object, <feed> in Atom 1.0 and <rss> in RSS 2.0.

Quoted: ProgrammableWeb has been doing a fantastic job chronicling web app APIs for over three years, and today they reached a milestone, surpassing 1000 APIs tracked. ProgrammableWeb is a great resource for developers cooking up great mashups, so kudos to them.

Quoted: The RESTful API serves as a common protocol understood by all OpenSocial 0.8-compliant clients and servers.

Quoted: Hammerhead adds a tab to Firebug for measuring the load time of web pages.