Genesis Framework: a popular framework by StudioPress for development Wordpress sites. It comes with SEO optimized code and airtight security features.
Destop Server: No more WAMP/MAMP/XAMP. Desktop Server allows you to quickly generate WordPress projects that run locally.
Search Engine Optimization (SEO)
Moz Beginner’s Guide to SEO is a free resource that provides comprehensive information on Search Engine Optimization.
Google SEO starter guide is a free resource on Search Engine Optimization put together by Google.
SEO Resource list of the SEO Ace has a great list of SEO blogs you can follow.
Learn Web Development (free)
Learn to Code HTML & CSS covers a variety of web design and development topics from beginning to advanced levels. The explainations are clear and the site is highly organized.
Odin Project is a complete curriculum for learning web development consisting of best online resources. The focus is on projects so you can learn by doing. It also offers opportunities to connect with other students so you don't have to learn on your own.
Code Academy offers free online courses that teach you the basics of a number of programming languages.
Web Development Tools
HTML 5 Outliner is a tool for visualizing the outline generated by HTML5 file.
Markup validation service is a tool for validating HTML code.
CSS validation service is a tool for validating CSS code.
XML Sitemap is a tool for creating sitemaps that are used by the major search engines to index your webpages accurately.
Resizemybrowser is a simple browser window resize app for Web designers and developers.
Can I use? is a terrific resources for browser support for different HTML and CSS properties.
deCSS3 is a tool that disabled any CSS3 features, allowing you to see what your website looks like without CSS3 and whether conditional styles are working.
Real Favicon Generator is a tool for generating favicons that work on most browsers and platforms.