IntraMessenger is a free application for that enables communication between communities, groups, companies or simply closed groups.

It consists of a client (for Windows) & a PHP-MySQL-based open source server to manage the whole communication.

The messenger is autonomous, but authentication (login + password) is possible from other existing databases like forums, groupware applications, e-learning systems, etc.

It can operate in 2 modes:

• open community : everybody can see everybody, without add to contact list
• groups only : everybody can see everybody (but only) is they are in the same group

IntraMessenger has a multilingual interface & it is a handy application for enabling web-based communities to communicate in the desktop.

MooEditable is a MooTools plugin that instantly converts a textarea field into a WYSIWYG editor.

It has a slick interface & comes with only the frequently used items like text formatting, lists, inserting images/links & undo/redo.

The plugin can also switch between design & HTML modes.

If you'd like to improve it further or customize to your needs,  It has a very detailed documentation.

JuiceKit is an open source software development kit (SDK), which integrates with Adobe Flex, for building "information experience" applications.

The SDK includes components for controls, visualizations & utility classes that are easy to implement & aesthetically pleasing.

To better define the SDK, some of the components it has are a treemap, US Map, "copying data to the computer's clipboard" & much more..

These components can be used independently, within other applications or assembled together to create full applications.

JuiceKit is very well-documented & there are few examples provided to show the things that can be created.

TufteGraph is a jQuery plugin that can create standard & stacked bar charts inside any given element.

It it configured mostly by dynamic functions which simplifies the usage by allowing for a really compact API.

A standard chart comes with no style but it can be totally customized with CSS (download package includes an example).

Important Info: The charts created work in major browsers. Although the example in the plugin's website doesn't seem to work in IE, the raphael.js file used can be replaced by the latest version of Raphaël JS library which will fix the problem.

JPEGCam is an open source Flash + JavaScript library that enables you to insert a custom-sized Flash movie in a webpage that captures Webcam snapshots.

After capturing the snapshots, it can submit them to any server in JPEG format (download package includes sample PHP 5 code).

The webcam is activated with the Flash movie which includes a full-canvas camera control with no flash user interface elements. User can decide when to take the snapshot & click a button to do it.

Every control for displaying the Flash device configuration panel & taking snapshots is handled from Javascript which makes:

• controlling the user interface
• using your own buttons and layout

possible.

JQuery Roundabout is an impressive plugin that converts HTML elements into highly-customizable & interactive turntable-like (and more) interfaces.

By default, it works with ordered/un-ordered lists but with a little configuration it can convert any nested HTML structure.

The plugin has a bunch of options for maximum customization like:

• optional starting element
• speed of the animations
• opacity & scale of objects
• ability to trigger animations from any element
• disabling clicks
• & more..

With the help of a complimentary plugin, named Roundabout Shapes, it is possible create too many different types of interfaces.

jQuery Roundabout can have have various uses from displaying images to creating form interfaces, animations, etc.

Google Browser Size is a visualization tool by Google Labs that shows any website behind an overlay of browser-window-sizes average

The overlay information is actually created from the data of people who visit Google (which won't be wrong to call it an average).

The tool is perfect for learning what percentage of the visitors are seeing the most important parts at initial load & what are they missing.

When you move the mouse, a rectangle which follows the mouse pointer enables us to interact with the website. And, optionally, the opacity level can be changed.

But, like mentioned, it is created with the data from google.com & will work for websites that target average internet users. It would be great to see this integrated into Google Analytics creating a custom overlay.

Meerkat is a jQuery plugin for creating a fixed content on the top or bottom of the page which keeps its position when the page is scrolled.

The content displayed can slide or fade in & can be configured with the options provided.

There is a close option, which closes Meerkat until the page has been reloaded, or a dontShow option, which closes it until the browser session has ended, or for a set amount of days, totally configurable.

It is also possible to define the background color, height & animation speed of the Meerkat easily.

The plugin is very useful for displaying sticky banners & notifications or creating a splash page (an example exists in the plugin page).

Clearbox 3 is a Lightbox-like modal box script to display images, image galleries & various other contents including Flash, Quicktime, Windows Media formats, HTML, inner content, etc.

It can show multi-line text information for any content displayed. And, as a unique feature, images displayed can be rotated with a click.

Clearbox supports slideshow functionality and every aspect of it can be customized from the settings of the script.

It is friendly with Ajax & can display content via Ajax calls.

Also, its interface can be presented in any language by supplying a language file.

P.S. Clearbox is free for only personal use.

nuBuilder is an open source web application for quickly creating web-based back-ends.

It allows you to create forms for inserting-updating data & generates reports with that data.

The back-ends are created with PHP/JavaScript & the data is stored in a MySQL database.

nuBuilder can be used to create complex applications like accounting systems or simple lists like customer phone numbers.

It  has built-in components like permissions, search screens & data validation that makes the development process faster.

The application can be expanded with modules & plugins.

nuBuilder is also a handy application for web developers who create a web-app & want to put it online as quickly as possible without spending time on building the back-end for it (at least for a while).