Just thought I would share a list of web development tools from my bookmarks. Hope they're useful to someone.

Code Validation

http://validator.w3.org/ HTML, XHTML, SMIL, and MathML Validation
http://jigsaw.w3.org/css-validator/ CSS Validation
http://validator.w3.org/checklink Link Validation
http://validator.w3.org/feed/ RSS and Atom Validation
http://www.totalvalidator.com/validator/ValidatorForm Checks spelling and other site factors
http://www.xmlvalidation.com/ An XML validator
http://www.stg.brown.edu/service/xmlvalid/ Another XML validator

Optimization and Testing

http://www.getfirebug.com/ The FireBug FireFox extension
http://developer.yahoo.com/yslow/ A FireBug plugin from Yahoo that tests page speed and give a grade on 14 factors
http://www.websiteoptimization.com/services/analyze/ Checks page size and speed
http://services.google.com/websiteoptimizer/ Google's website optimizer
http://www.websitegrader.com Gives your site an SEO grade
http://vandelaydesign.com/blog/tools...-your-website/ A long list of analytics and optimization tools

Emulators

http://browsershots.org/ Test your site in different browsers

Code Compression

http://www.cleancss.com/ A CSS code compressor
http://www.cssdrive.com/index.php/main/csscompressor/ CSS code compressor
http://tools.arantius.com/css-compressor Yet another one for CSS
http://www.julienlecomte.net/blog/2008/01/42/ JavaScript and CSS
http://dean.edwards.name/packer/ A JavaScript compressor
http://javascript.crockford.com/jsmin.html JavaScript

Generators

http://www.smashingmagazine.com/2006...ne-generators/ A ridiculously long and useful list of generators including some for ASCII, color, CSS, domain names, emails, favicons, flash, forms, graphics, .htaccess, metatags, passwords, pdfs, PHP, popups, robots.txt, RSS, sitemaps, text, tooltips, weblogs, xml, and more
http://pinoy-blog.isoftinno.com/2007...ne-generators/
Another long list of generators

Analytics

http://www.feng-gui.com Simulates eye-tracking, but not foolproof- free
http://www.fusestats.com/ An analytics package, free trial, paid premium options
http://crazyegg.com/ Another analytics package, free trial, paid premium options
http://www.google.com/analytics/ In case you didn't know about it - free
http://www.w3counter.com/ Another free trial, paid premium option

Mobile

http://www.w3schools.com/wap/default.asp A WAP/WML tutorial
http://code.google.com/android/ Google's mobile platform
http://mtld.mobi/emulator.php Test your site's appearance for mobile phones
http://iphonetester.com/ Test your site's appearance on the iphone
http://www.marketcircle.com/iphoney/ A downloadable program to test for the iphone
http://www.mobisitegalore.com/ Build an ad-supported mobile site for free

Design

http://www.colourlovers.com/ Helps you choose your site's colors
http://www.joehallock.com/edu/COM498/index.html A study on color
http://www.virtualhosting.com/blog/2...cking-studies/ An article about scientific web design
http://developer.yahoo.com/ypatterns/index.php The Yahoo Design Pattern Library
http://groups.ischool.berkeley.edu/u...terns/home.php
A UC Berkeley resource for building user-interfaces
http://www.bluevertigo.com.ar/bluevertigo.htm A great resource for all sorts of design elements to include on your sites including stock photography, fonts, brushes, logos, clip art, sounds, icons, and more
http://psychology.wichita.edu/surl/u...ws/3S/font.htm A font usability study
http://ilovetypography.com/ A site about typography

Widgets, Apps and APIs

http://code.google.com/apis/opensocial/ Google's Open Social network app development center
http://developers.facebook.com/ Build apps for facebook
http://sproutbuilder.com/ A widget builder (still in beta)
http://www.amazon.com/gp/browse.html?node=3435361 Amazon's API
http://www.paypaldeveloper.com/ PayPal's developer community
http://developer.revver.com/ API for Revver, a video sharing site
http://code.google.com/apis/youtube/overview.html YouTube's API
http://code.google.com/apis/maps/ Google Maps API
http://code.google.com/more/ All of Google's APIs
http://apidoc.digg.com/ Digg's API
http://www.widgetbox.com/ A widget creation tool and library
http://www.addthis.com/ A social bookmarking widget
http://openid.net/developers/ Make your site OpenID enabled
http://twitter.com/help/api Twitter's API
http://developer.authorize.net/ Authorize.net API


Code Frameworks

http://mootools.net/ A JavaScript framework
http://jquery.com/ Another JavaScript framework
http://www.prototypejs.org/ Another JavaScript framework
http://script.aculo.us/ User interface component for Prototype
http://developer.yahoo.com/yui/ Yahoo's User Interface Library
http://www.adobe.com/products/air/ Adobe's AIR
http://framework.zend.com/ An open source PHP framework
http://pear.php.net/ Another PHP framework
http://www.contentwithstyle.co.uk/Articles/17/ A CSS framework?

RSS and Atom

http://searchenginewatch.com/showPage.html?page=2175271 An RSS tutorial
http://www.syndic8.com/ A feed directory
http://pipes.yahoo.com/pipes/ A feed aggregator and manipulator
http://www.feedburner.com Hosts, builds, and distributes feeds

Tutorials

http://developer.yahoo.com/yui/theater/ Over 40 video tutorials and presentations - Highly recommended
http://www.htmlcodetutorial.com/ Learn HTML
http://www.tizag.com/ Tutorials for HTML, CSS, PHP, PERL, AJAX, ASP, VBScript, XML, SQL, MySQL, and Flash
http://www.w3schools.com/ Tutorials on most web-based programming languages
http://www.howtocreate.co.uk/tutoria...ript/important A JavaScript tutorial
http://www.simple-talk.com/sql/datab...sign-mistakes/ An article on database design
http://about.stompernet.com/library More video tutorials, though some are product advertisements

Script Libraries

http://sourceforge.net/ All open source, all languages- have fun!
http://www.ajaxrain.com Over 1000 AJAX snippets
http://www.hotscripts.com/ Another large collection in multiple programming languages
http://www.dynamicdrive.com/ A DHTML and JavaScript library
http://www.phpclasses.org/ An ugly and annoying site that actually provides very useful PHP classes
http://regexlib.com/ A library for Regular Expressions

Keyword Research Tools

https://adwords.google.com/select/KeywordToolExternal Google's keyword helper
http://freekeywords.wordtracker.com/
http://www.wordtracker.com Paid service
http://inventory.overture.com/ I couldn't get it to load, but it should be there

Miscellaneous But Useful

http://www.456bereastreet.com/ Articles and news on web standards, accessibility, and usability
http://www.alistapart.com/ A webzine for developers
http://www.thinkvitamin.com/ A web developer resource
http://mashable.com/2007/10/27/creative-commons/ 25 sources for creative commons content
http://mashable.com/2007/10/14/web-coding/ Over 250 web development resources
http://24ways.org/ A series of great articles that come out every year
http://www.csszengarden.com/ See what you can do with CSS

That's all I'm going to post today, but I might post some more in the future. I hope they help you. Feel free to add your own below.

This was very nice of you. I too have a lot of these sites bookmarked.

Q...

Thanks for this, there's quite a few here I didn't know of.

lovely list
thanks for sharing this

there's some amazing stuff on this list ive been trying a couple out thanks a lot

Thanks muchly! Alot of great/helpful stuff there.

No problem, everyone. Be sure to add your own as well and I'll edit the list to include your suggestions too.

Pls add my sig link to your list ,Over 230 High Quality Royalty Free icons set for your blog or website.
Hope they are useful to someone

thanks

Semantic Web

http://www.ysearchblog.com/archives/000527.html Yahoo is supporting semantic web formats
http://microformats.org/ A site describing microformats, with news updates
http://microformats.org/wiki/hcard A description of hCard
http://microformats.org/wiki/hcalendar A description of hCalendar
http://microformats.org/wiki/hreview A description of hReview
http://microformats.org/wiki/hatom A description of hAtom
http://microformats.org/wiki/xfn A description of XFN
http://en.wikipedia.org/wiki/Dublin_Core Overview of Dublin Core
http://dublincore.org Official Dublin Core website
http://www.foaf-project.org/ The FOAF project
http://www.georss.org/ GeoRSS website
http://search.yahoo.com/mrss MediaRSS specification
http://www.w3.org/TR/xhtml-rdfa-primer/ Primer for RDFa
http://en.wikipedia.org/wiki/Embedded_RDF Description of eRDF
http://www.xml.com/pub/a/2001/01/24/rdf.html Article explaining RDF
http://www.rdfabout.com/ Explains RDF
http://www.w3.org/RDF/ W3C specification for RDF
http://www.w3.org/TR/owl-features/ W3C specification for OWL

Internationalization and Localization

http://unicode.org/cldr/index.html Provides local equivalents for countries, languages, measurements, date and time formats and more
http://code.google.com/apis/ajaxlanguage/ Google's translator as an API
http://www.w3.org/International/ W3C site on internationalization

9ice One,

To check Image Accessibility www.juicystudio.com/services/image.php
To Check ContentReadability www.juicystudio.com/services/readability.php
To Check Colour Contrast www.juicystudio.com/services/colourcontrast.php
To Check CSS Colour Contast www.accesskeys.org/tools/color-contrast.html
To check Image Accessibility www.juicystudio.com/services/image.php
To Check Page's Link www.validator.w3.org/checklink
To check page's CSS www.jigsaw.w3.org/css-validator
To check page's Html www.validator.w3.org

great listing. Thanks!

A good list, I have bookmarked some of them, Than you

That is a great list. Thanks for sharing it!

Another great tutorial is http://css.maxdesign.com.au/floatutorial/

This site is also pretty cool http://designmeltdown.com/