Flash Gallery is a free flash gallery application with Flickr photostream & auto-thumbnail creation support.
The application scans the related folder, creates the thumbnails & uses filenames for titles.

Flash Gallery requires PHP to run but this is not needed if you’re streaming Flickr images.
The application has a customizable design, full-screen support & it is fully resizeable.
Requirements: PHP (if Flickr is not used)
Timeago is a jQuery plugin which enables you to display fuzzy timestamps. And, the timestamps are auto-updated.
Some example timestamps are "5 minutes ago, about 2 days ago".

Using Timeago is very functional for displaying more friendly timestamps and auto-update feature makes it more accurate when a page is opened for a while.
P.S. John Resig also has a similar solution named JavaScript Pretty Date.
Requirements: jQuery
Compatibility: All Major Browsers
SQL Buddy is an open source web-based MySQL administrator with an Ajaxed interface.
It requires no setup and works once the files are uploaded.

SQL Buddy handles logins with the MySQL user tables. Ordering & resizing the columns makes browsing easier.
Although browsing is mostly with Ajax, the application is browser back-forward friendly. And, it enables you to import/export to/from .CSV files.
Requirements: PHP 4.3+, MySQL 4+
Compatibility: All Major Browsers except IE6
Gregarius is an open source web based feed reader. It is similar to Google Reader but you can install in on your servers.
It has a very simple & functional interface with a password protected administration area.

This feed reader has Ajaxed item tagging & full-text search features. It is committed to web standards: renders XHTML/CSS, supports OPML.
The application is built with PHP & uses MySQL or SQLite for storing the data.
With a getting active community, Gregarius has multiple themes & plugins.
Requirements: PHP 4+ & MySQL or SQLite
Compatibility: All Major Browsers
Zoki Poll is a free PHP - Ajax poll script that stores data in a XML file.
It has flexible display options for integrating the poll in limited spaces like horizontal scrolling long question & answers or vertical scrolling of answers.
Vote results are displayed with a nice, animated percentage bar & the look of the poll can be easily changed via CSS.
To prevent duplicate voting, Zoki Poll has a cookie-based protection system.
This Ajax poll script does not have an administration interface & it is a nice piece of code if you’re ready to integrate it yourself.
P.S. Downloading the script requires free registration.
Requirements: PHP 4.3.2+
Compatibility: All Major Browsers
Imago is an Ajax image gallery built with MooTools.
This gallery has connectors for Flickr, SmugMug & SimpleViewer to call images from them or use their XML files.

Imago is fully customizable with CSS & very easy to use.
A detailed "how to use" information guides you on setting up your Ajax image gallery.
Requirements: MooTools
Compatibility: Flickr, SimpleViewer, SmugMug or hosted images.
This is a free streaming Flash MP3 player that is easy to use & customize as it comes with the .FLA file.
The player uses a XML file where its design can be customized and the song to be played can be mentioned.
.jpg)
The player plays 1 song which makes it ideal for using it as a website background music player or can be improved further.
It is written with Flash8 / AS2.
jqGrid is an Ajaxed jQuery grid plugin with amazing features.
As the grid is a client-side solution that loads data with Ajax callbacks, it can be used with any server-side language like ASP, PHP, ASP.NET, JSP and so.
A clever feature is sub grids which shows you a sub grid when a master column is called.

Some features of jqGrid:
- paging functions
- add, edit, delete & search records
- accepts XML, JSON, array or user data as input
- multiple selection of rows
- sub grid & grid details (great feature!)
- UI datepicker integration
- & more…
jqGrid is very impressive with the interface, features, usability & documentation. To check this great jQuery grid plugin, click here.
Requirements: jQuery 1.1.4+
Compatibility: All Major Browsers
Raphaël is a JavaScript library that facilitates using & creating vector graphics in websites.
It uses SVG & VML for creating graphics. As every graphic generated is a DOM object, you can manipulate them via JavaScript.

This graphics JavaScript library is very ideal for creating charts, images effects like rotation or reflection.
An example:
Creating graphics is much easier with Raphaël compared to writing everything from scratch as a circle can be created with:
paper.circle(320, 240, 50).attr({fill: "#223fa3", stroke: "#223fa3", "stroke-width": 3, "fill-opacity": 0.5});
The library currently works in all major browsers except Firefox 2 & it is still under development.
Requirements: No Requirements
Compatibility: Firefox 3.0+, Safari 3.0+, Opera 9.5+ and Internet Explorer 6.0+
This is a nice animated menu built with MooTools.
The trick of the menu is a Flashy hover effect of the arrow (or any element you want).

To use this menu script, you don’t even have to play with JavaScript except defining the variables:
- background image container
- nav elements
- current nav element’s div id
- background image’s y coordinate
- left offset of the image
A well-described usage of the menu including the download of all the necessary files can be found at the script’s website.
Requirements: MooTools 1.2+
Compatibility: All Major Browsers