Books

• Confident Ruby https://shiprise.dpdcart.com/
• Objects on Rails https://shiprise.dpdcart.com/
• Working With UNIX Processes https://www.jstorimer.com/pages/books
• Working With Ruby Threads https://www.jstorimer.com/pages/books
• https://computationbook.com
• Don’t Make Me Think http://sensible.com/dmmt.html (UX / usability)

Articles

• https://agilemanifesto.org/principles.html
• https://www.joelonsoftware.com/2000/10/02/painless-functional-specifications-part-1-why-bother/

Blogs

• https://afreshcup.com
• https://www.postgresql.org/about/newsarchive/
• https://weblog.rubyonrails.org/
• http://highscalability.com

Emails

• https://rubyweekly.com
• http://postgresweekly.com/
• https://cooperpress.com/publications/

Other

• https://thoughtbot.com/upcase