I just want to centralize my findings and bookmarks in a central location, and share them.

Collaboration

• Ben Balter - 15 rules for communicating at GitHub
• Dale Emery - model of motivation : Motivation = Ability × Results × Preferences
• Jbrains.ca - What If We Forget To Write the Tests?

• Paul Kaye - Control stifles creativity and growth

Free Online tools

• BuiltWith - Find out what technology a website is built with
• Dillinger - Online Markdown Editor
• Air Mail - temporary email service
• StackEdit - in-browser markdown editor
• XKPasswd - secure memorable password generator inspired by XKCD
• YouTube to MP3 converter

Gaming

• BoardGameGeek - most complete board game database that holds tons of reviews, images and videos
• IsThereAnyDeal.com - keep track of the best deals for video games you'd like to play

Health and Work-Life Balance

• Matt Might - Tips for work-life balance
• Simple Programmer - Stop Improving Yourself

Productivity

• Medium - The 30 second habit with a lifelong impact
• Jbrains.ca - The Two-Minute Rule / When You’re Buried in Email
• Jbrains.ca - Flow Requires Focus, Not Time
• BugMeNot - enter a domain or url and find shared logins
• The Minds Journal - A Japanese Technique for Overcoming Laziness / Kaizen, Or The One-Minute Principle
• Foundr - GTD : Superpower Your Productivity With Pen and Paper
• HuffPost - 11 Tweaks to Your Morning Routine
• Gojko Adzic - Splitting user stories -- the hamburger method
• Jeff Haden - 10 Steps to Make Each Day Exceptionally Productive

Troubleshooting

• pluralsight - 3 troubleshooting tips that can save you a world of time

Linux

• OSTechNix - How To Securely And Permanently Delete Your Data In Linux
• kahun/awesome-sysadmin - A curated list of amazingly awesome open source sysadmin resources
• Binh Nguyen - (2004) Linux Dictionary
• Gareth Anderson - (2006) GNU/Linux Command-Line Tools Summary

Music

• Rate Your Music - one of the most complete music database for cataloging, tagging and reviewing your music collection
• TasteKid - get recommendations for music but also tv shows, films, games, books...

Photography

• Exposure-Mat - build yourself a free light meter that fits in your wallet.

Programming

• Mastodon - take a break from twitter and switch to one of mastodon instances.
• InfoQ - news, videos, books for software developers
• /r/programming - reddit about programming
• Hack Reactor - Infographic of productivity tips for developers, to share with your teammates
• javarevisited - 11 Tips to become a better Interviewer?
• 10 C99 tricks
• Java Performance Tuning - regular tips and news about java performance tuning

Clean Code

• Clean Code Cheat Sheet v2.4 - cheat sheet for clean code

Containers

• DEV - Mikes monster list of docker tips
• Docker Documentation - Best practices for writing Dockerfiles
• Sonatype - KISSSSS : good approach to ensure you're successful with containers
• SlideShare - Optimizing Docker Images

Git

• Dissecting Git's Guts - Git Merge 2016 + Cheat Sheet of git commands
• 20 Tricks with Git and Shell - Git Merge 2016
• 25 Tips for Intermediate Git Users

Productivity

• Java Code Geeks - 10 Productivity tips for software developers
• Jbrains.ca - Avoiding Distractions While Programming
• Moran Danieli-Cohen - 3 Effective Ways to Maintain High Energy Levels at Work for Software Engineers
• Clean Coder Blog - Blue. No! Yellow! Comparative Productivity of Programming Languages
• Paul Graham - How Context Switching destroys Developers Productivity and how to fix it.

Programmer humor

• CommitStrip - daily life of developers
• Geek&Poke - cartoons
• The Profound Programmer - Programming frustrations expressed through profane, beautiful photographs

Scripting

• Bash Hackers Wiki - obsolete and deprecated syntax
• Bash Pitfalls - common errors that Bash programmers make
• ShellCheck - finds bugs in your shell scripts.
• Nicola Paolucci - Ten tips for wonderful bash productivity
• blockloop.io - Mastering Bash and Terminal
• kvz.io - Best Practices for Writing Bash Scripts
• Matt Might - 3 shell scripts to improve your writing
• Quickshiftin - Template method pattern in BASH
• Fahd Shariff - Shell Scripting - Best Practices
• Fahd Shariff - Shell Scripting: <, << and <<<
• Nitin Bhadauria - Foolproof Your Bash Script – Some Best Practices
• David Pashley - Writing Robust Bash Shell Scripts
• Paul Armstrong - Shell Style Guide by Google
• Aaron Maxwell - Use the Unofficial Bash Strict Mode (Unless You Looove Debugging)
• Aaron Maxwell - How "Exit Traps" Can Make Your Bash Scripts Way More Robust And Reliable
• Ray Smith - [PDF] Shell Scripting Craftsmanship
• Pádraig Brady - Common shell script mistakes
• Mendel Cooper - Advanced Bash-Scripting Guide / An in-depth exploration of the art of shell scripting

Security / Penetration Testing

• highon.coffee - Penetration Testing Tools Cheat Sheet

Testing

• Aaron Maxwell - Building a Automated Testing/Quality Assurance System