Web 2.0 is a bit ineffable: Nobody knows what is, but they know it when it they see it. In this article, we take a look at 10 Web 2.0 apps helping to define the next generation of Internet software.Web 2.0 means a lot of things to a lot of people. But while the term remains a bit ineffable, Web apps that take advantage of the new paradigm are very real, and cropping up fast. Below, a look at some of the more interesting and helpful applications to spring from Web 2.0 technologies.
Office Productivity
Writely.com and Fckeditor.com
If you haven't heard of writely.com by now, get thee out from under your word processor. Writely is an AJAX (Asynchronous JavaScript and XML)-powered Web app that allows you to create and edit documents through your browser. No downloads needed, unless you save your document to disk. You can upload a Word file, html, text or an image, and work on it by your lonesome or with a group. Writely includes features you'd expect from a desktop application like Word, such as text formatting, table inserts, and more. Fckeditor.com is a similar service. And, although the name lends itself to salacious interpretations, the service is named after the creator, Frederico Caldeira Knabben.
gOffice
Another site that offers Web word processing. GOffice is very simple to use, even though its menu is a jumble of buttons. It's free for personal use, and $1 per month for a business account that allows you to upload your own letterhead. Documents are created and saved as PDFs.
Num Sum
If writely.com is Word for the Web, then Num Sum is Excel. Num Sum's free account lets you create and edit spreadsheets. You can then tag those spreadsheets and share them amongst co-workers and friends.
S5
Eric Meyer's standards-based slideshow tool has been around a bit longer than the previously mentioned tools, and it's not a Web app (so it's not AJAX-based). But S5 is an amazing, lightweight slideshow format based entirely on XHTML, CSS and JavScript. And, of course, since the slideshow is standards-based, your slideshows look and work smoothly on the Web.
SimplyHired
Since we're talking about office productivity, we might as well mention SimplyHired, a job search engine. While the engine itself isn't AJAX-powered, the rating widget beside each job revealed by your search is. As you rate the jobs you searched for, the engine will ostensibly use your ratings to pare down results. This rating system can also be found on sites like netflix.com.
Tools and Tricks and Lists
WebNote
WebNote is a note-taking Web app. You type something down, save your workspace, and then revisit it from any computer. You can drag windows, resize them, and apply some basic text formatting.
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Ajax IM and Meebo.com
These two browser-based instant messaging clients use the XMLHTTPRequest object in JavaScript to send commands to and from the server. Ajax IM requires you to download an installation package. Meebo, on the other hand, allows you to sign in to one of six IM clients (AIM, ICQ, Yahoo! Messenger, MSN, Jabber or GTalk).
Rollyo
Rollyo is a personalized search engine service that allows you to customize which groups of sites you search at one time. Based on Yahoo! Search, Rollyo also lets you share your search "rolls" with friends. Really want to know what sites Jay Rosen or Jeff Jarvis are searching? Check them out on the Explore Searchrolls page.
Trying to control digital content is insane. Click here to read more.
sIFR
Scalable Inman Flash Replacement is a font replacement tool. The javascript/CSS/Flash tech is meant to replace short passages of plain browser text in a typeface of your choice, regardless of whether a user viewing your page has that font installed on their system. sIFR is fully accessible to screenreaders, and can be copied and pasted. Amazing.
Backpack
Backpack is the little brother of 37 Signals' Basecamp, and it lets you store notes, photos and files online. You can also publish your pages for others to see and schedule reminders to be sent via SMS to your phone.
Web Design 
