Useful tools when creating a new website

This is a list of tools I used to be efficient when working with launching a new website (based on DotNetNuke):

• NotePad++  is a free source code editor and Notepad replacement that supports several languages. Running in the MS Windows environment, its use is governed by GPL License. Based on the powerful editing component Scintilla, Notepad++ is written in C++ and uses pure Win32 API and STL which ensures a higher execution speed and smaller program size
• GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. 
• Google Chrome Developer Tools
• Google Chrome YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages. YSlow grades web page based on one of three predefined ruleset or a user-defined ruleset. It offers suggestions for improving the page's performance, summarizes the page's components, displays statistics about the page.