Firefox has Web Developer plugin and Firebug for troubleshooting html/css/javascript issues. Google Chrome and Safari have a very similar console and right-click options for "Inspect Element".
Does IE7 have anything similar for troubleshooting layout/html/css issues?
Web Development Helper is a free browser extension for Internet Explorer that provides a set of tools and utilities for the Web developer, esp. Ajax and ASP.NET developers. The tool provides features such as a DOM inspector, an HTTP tracing tool, and script diagnostics and immediate window. Web Development Helper works against IE6+, and requires the .NET Framework 2.0 or greater to be installed on the machine. Once installed, the tool can be activated using the Tools | Web Development Helper command. You can also customize your browser's toolbar to add a button for this command to facilitate frequest use. Clicking on the menu command or browser button brings up the tool's console window and set of commands. Page Features: DOM inspector allows viewing all elements, selected elements, or elements matching an ID or CSS class, their attributes and styles. Capturing a screen shot of the current page. Viewing page information such as metadata, tags, and linked resources. .......
There's a toolbar you can get but it still doesn't match up to Firefox, especially for javascript debugging.
IE8 will be a huge improvement for development.
You can also use IE watch, which is like firebug, but you need to buy it. It is a 30 days trail version.
You can also use Firebug Lite, wich works on IE, Opera and Safari.
Its a javscript implementation that you can load with a simple bookmarklet.
As SO doesn't allow javascript, here is the bookmarlet source code (just copy paste to your browser location bar (always make sure its safe before executing random javascript (In any case check the first link)))
javascript:var%20firebug=document.createElement('script');firebug.setAttribute('src','http://getfirebug.com/releases/lite/1.2/firebug-lite-compressed.js');document.body.appendChild(firebug);(function(){if(window.firebug.version){firebug.init();}else{setTimeout(arguments.callee);}})();void(firebug);
Firebug Lite supports all basic commands of Firebug.
unfortunately it seems microsoft have discontinued it, the page for the toolbar now just says 'We are sorry, the page you requested cannot be found.'
I reckon because its built into 8 they have removed it for download, and cant be bothered with helping out us devs who are forced to make our projects work in their more archaic browsers :'(
Also before anyone says it, IE8 compatability mode != IE7