Learn
Developer tools and Tutorials.
Learn new technologies in a web browser. https://www.katacoda.com
Tutorials for dev-ops and activities on Ubuntu machines. https://ubuntu.com/tutorials
How-tos, tutorials, tips and tricks, and more. https://www.redhat.com/sysadmin/
DevOps Resource Center /https://docs.microsoft.com/en-us/azure/devops/learn,
Learn automation by doing it. Right now, right here, in your browser. https://go.nrelabs.io/catalog/
Development and sysadmin tutorials. https://www.digitalocean.com/community/tutorials
How-tos, tutorials, tips and tricks, and more. https://www.redhat.com/sysadmin/
Compiler, IDE, interpreter, REPL and Real-time collaborative. https://repl.it
Simple bite-sized DevOps Screencasts (released weekly). https://sysadmincasts.com/
Machine Learning platforms.
Managed cloud platform for data science https://www.floydhub.com
Open source machine learning platform https://www.tensorflow.org
Questions, answers and tips.
Reviews of popular open source tools https://stackshare.io
Question and answer site for security professionals.https://security.stackexchange.com
Cyber Security.
Protec your organisation from cyber attacks. https://www.itgovernance.co.uk/what-is-cybersecurity
The Open Web Application Security Project (OWASP). https://www.owasp.org
Linux Moblie Phones.
Open-source operating system based on Linux. https://puri.sm/products/librem-5
Android apps.
Linux Command Library, works 100% offline, https://play.google.com
JavaScript Quiz Test your JavaScript skills. https://play.google.com
Vim Master Learn to use the best text editor. https://play.google.com
DroidVim is a Vim clone text editor ported for Android. https://play.google.com
Termux terminal emulation Linux with package collection. https://play.google.com
Lectures and Podacsts.
Computer Science course at Harvard Extension School. http://cs75.tv/2012/summer/