Interesting html FORM Validators for web developers
http://woork.blogspot.com/2009/02/interesting-html-form-validators-for.html

This post illustrates how to use some interesting HTML Form validators to check FORM fields writing only some lines of HTML and JavaScript code. All these proposal are lightweight, cross-browser and simple to use and customize in your web projects in few minutes.

… an assistive tool for web developers, that allows you to quickly review code quality and semantic structure of any website (particularly those based on YAML) as well as testing it against common oversights.

RED (Resource Expert Droid) checks HTTP resources to see how they use HTTP, makes suggestions, and finds common protocol mistakes

Jquery Inline Form Validation Engine

Ways to check to see if your website conforms to generally accepted standards of web design

総まとめ。まさにいま役に立つ

15 Tools for Testing your Website

If you want to have the same experience over multiple browsers and different machines then testing your website is vital. In this article I’ve gathered some of the most important tools that you can use in testing your site against various errors – CSS Errors, HTML Errors, Crossbrowsing Errors etc.

SitePoint Blogs: News, opinion, and fresh thinking for web developers and designers

(...) So make it sure that you go through this post and run all the necessary tests on your website before making it live.