Tips, Tricks, Scripts and Tools Web Developers must know

Here is a collection on the tips, tricks, scripts and tools web developers must know:

Tools & Web Apps 

13 Most Essential Open Source Apps That You Probably Like To Say Thank You
14 free tools that reveal why people abandon your website
40+ CSS Generators, Creators, and Makers
74 Great Web Apps for Web Designers we have forgotten about
50-Plus Tips and Resources to Improve Your Site’s Speed and Performance
15 Tools for Monitoring a Website’s Popularity
11 Powerful Firefox 3 Add-ons That Can Replace Standalone Applications
10 Free Photo Managing Software You Should At Least Know
15 Things Every Web Developer Should Be Thankful For
15 Must-Have Bookmarklets For Web Designers And Developers
20 Great PHP frameworks for developers
66 Links To Learn The Webdesign Basics
Web Development Toolbox: 120+ New Tools for Web Development

Scripts, Tweaks and Hacks

The Top 40 Free Ajax & Javascript Code for Web Designers
15 Key Elements All Top Web Sites Should Have
Top 10 Tutorials for Converting PSDs to HTML/CSS
30+ Tooltips Scripts With JavaScript, Ajax & CSS
50+ Nice Clean CSS Tab-Based Navigation Scripts
40+ Most Wanted Wordpress Tricks and Hacks and 30+ More
30+ Eye-Opening Web Development Screencasts
19 CSS Menu Tutorials to Spice Up Your Web Designs
34+ free HTML newsletter templates for startups
50 Excellent AJAX Tutorials
15 Helpful In-Browser Web Development Tools
75 (Really) Useful JavaScript Techniques
63 Essential Wordpress Hacks, Tutorials, Help Files and Cheats
The Best (19) Cheat Sheets for Web Designers and Developers (From CSS, Ajax, Perl, Vbscript…)
10 Useful RSS-Tricks and Hacks For WordPress
20 Amazing Javascript Prototype Scripts, Elements, Widgets, Classes..
10 Smart Javascript Techniques to Improve Your UI
20 Excellent AJAX Effects You Should Know
35 Easy to use Free Ajax/Javascript Navigation Solutions
Top 10 CSS buttons tutorial list
10 Free Chart Scripts

Tips 

10 Principles of the PHP Masters
6 Easy Ways to Improve Your HTML Emails
7 Principles Of Clean And Optimized CSS Code
12 Principles For Keeping Your Code Clean
10 Advanced PHP Tips To Improve Your Programming
10 Optimization Tips
10 SEO elements all websites should have
10 Web App Tips From 8 Inspirational Speakers
7 ways to write beautiful code
10 Dirty Little Web Development Tricks
15 CSS Tricks That Must be Learned
101 CSS Techniques Of All Time- Part 1 and Part 2

Sources 

20 Websites to Help You Master User Interface Design
53 Steps to follow if you want to become Freelance Web Designer/Developer (60+ Resources)
A study in Ajax Web trends. What are the best Free Ajax Resources? (70 of the Best Ajax Resources)
155 Wordpress Resources, Tutorials, Plugins, Themes, AJAX, Podcasting…WP Monster List
41 of the Best MooTools Ajax Example Downloads
65 Excellent jQuery Resources (tutorials,cheat sheets,ebooks,demos,plugins…)
37+ Great Ajax, CSS Tab-Based Interfaces

Generators

25 Color Palette Generating Resources for Web Designing!
13 Free Online Tools That Helps You To Create And Host Your Website
25 Web 2.0 Generators

Plugins and Themes

10 Best Plugins To Get More Comments
The top 20 plugins to transform Wordpress in a CMS
10 plugins you should be using in your Wordpress theme or blog
10 Wordpress Plugins to Add Ratings and Polls to your blog
Top 30 Wordpress Plugins that are actually useful!
130 WordPress Plugins You Could Ever Need: The Best Of : Part 1 and Part 2
18 Wordpress Plugins to add Professionalism to your Blog
7 Wordpress Themes To Create Your Own CSS Gallery