Tile5 is an open source HTML5 mapping JavaScript library that enables developers to integrate existing mapping platforms for providing a rich HTML5 experience.

It is compatible with most of the mapping providers like Google, Bing, Yahoo, MapQuest and more.

Besides the API for mapping, the library is also functional for creating moregeneric tiling application interfaces.

With the compatibility HTML5 offers, Tile5 is targeted at both desktop and mobile browsers.

Tip: there are very nice demos offered to see the power of the library.

Compatibility: HTML5 Enabled Browsers
Website: http://www.tile5.org/
Demo: http://www.tile5.org/demos/
Download: http://www.tile5.org/download

Cloud9 IDE is an open source application that aims to provide a powerful and focused IDE for JavaScript developers.

It is powered by the Ajax.org platform + makes use of HTML5, node.js, socket.io and many other projects.

The application has a pretty fast text editor with bundled syntax highlighting support for JS, HTML, CSS and mixed modes.

Cloud9 IDE has integrated debuggers for node.js and Google Chromewhich can be started, paused and stopped from the IDE.

Using WebDAV, it can connect to remote workspaces too and has a plugin system for improving it further (already has several bundled plugins).

P.S. The application is still in early development stages, can be a little buggy but improved continiously.

Requirements: Git 1.7+ (for Windows installations)
Website: http://www.cloud9ide.com/
Download: http://github.com/ajaxorg/cloud9

Liquidicity, a blog on design and technology, is sharing a huge set of flag icons with over 240 unique items.

They come in multiple sizes (16×16, 24×24, 32×32, 48×48, and 64×64) with 2 variants: flat and standard shiny one.

The icons are in .PNG format and organized by country name + ISO-3166-1 alpha-2 country code where available.

Website: http://www.gosquared.com/liquidicity/archives/1493

While creating content for the web, whether it is a blog post or a product for an e-commerce website, we're usually limited with the size of the images.

PHP Image Editor is an open source resource (paid for commercial projects) which can easily be integrated with any CMS and enables users to edit images.

It can resize, crop or rotate images and apply simple filters on them.

The script can be implemented quickly, just show the path of the image to be edited and that's all. Or, if you're using Joomla, there is a module for that.

Also, the interface is multilingual and there are already multiple languages waiting ready to be used.

Requirements: PHP5+, GD Library 2.0.28+
Compatibility: All Major Browsers
Website: http://phpimageeditor.se/
Demo: http://phpimageeditor.se/phpimageeditor/index.php?im...
Download: http://phpimageeditor.se/download.php

Google Chrome Frame is an open source Internet Explorer plugin that enables IE to use the open web technologies and speedy JavaScript engine of Google Chrome.

It is actually not so fresh and around for a while, however, the stable version of the plugin is released lately and it is ready-to-use.

The plugin requires 2 steps to work:

• The user with IE 6, 7 or 8 should install it
• The website must add a tag to the web pages (detecting IE users and inserting the tag only for them is a good idea)

After that, any user with those IE versions will have a browser with better capabilities like support for HTML5, CSS3, better JS performance and more.

Google Chrome Frame is already used by many popular websites including DeviantArt, github or HootSuite.

It is definitely not a perfect solution as "a step from end users are required" but at least a step forward and almost doesn't add an extra effort for web designers/developers.

Requirements: Windows 7 / Vista / XP SP2
Compatibility: IE 6, 7 and 8
Website: http://www.google.com/chromeframe/