SharePoint Tools

1. AC’s VS CodeRush/Refactor Tools for SharePoint Developers - Additions for CodeRush & Refactor! Pro Visual Studio productivity add-ins created by Andrew Connell. These include a dynamic list for SharePoint types, XML templates addressing the various XML files we use in SharePoint (eg: Feature schema, solution schema, field type definitions, *.webpart files, etc) as well as some refactorings.
2. CAML Query Builder
3. STSDEV - STSDEV is a proof-of-concept utility application which demonstrates how to generate Visual Studio project files and solution files to facilitate the development and deployment of templates and components for the SharePoint 2007 platform including Windows SharePoint Services 3.0 (WSS) and Microsoft Office SharePoint Server 2007 (MOSS).

.NET Tools

1. LINQPad

Web Tools

1. Firebug - Firebug integrates with Firefox to put a wealth of development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.
2. YSlow for Firebug - YSlow analyzes web pages and tells you why they’re slow based on the rules for high performance web sites. YSlow is a Firefox add-on integrated with the popular Firebug web development tool.
3. IE Developer Toolbar - Close to Firebug but not there yet
4. CSS Vista: A tool to compare CSS between IE and FireFox
5. Fiddler - Fiddler is a HTTP Debugging Proxy which logs all HTTP traffic between your computer and the Internet. Fiddler allows you to inspect all HTTP Traffic, set breakpoints, and “fiddle” with incoming or outgoing data.
6. SitePoint - New Articles, Fresh Thinking for Web Developers and Designers
7. IETester - IETester is a free WebBrowser that allows you to have the rendering and javascript engines of IE8 beta 1, IE7 IE 6 and IE5.5 on Vista and XP, as well as the installed IE in the same process.

Development Tools

1. Code Convertor - Converts C# to VB.NET and vice versa
2. NotePad++