Packt

Testbook

testbook.com

O'Reilly Learning

oreilly.com

RedShelf

redshelf.com

Javatpoint

javatpoint.com

Tutorials Point

tutorialspoint.com

OpenStax

openstax.org

Google Tech Dev Guide

techdevguide.withgoogle.com

zyBooks

zybooks.com

CodeProject

codeproject.com

PragmaticLinux

pragmaticlinux.com

Tech Interview Handbook

techinterviewhandbook.org

Bookboon

bookboon.com

SkillPress

skillpress.io

egghead.io

egghead.io

TradePub.com

tradepub.com

IntechOpen

intechopen.com

Ebookany

ebookany.com

Patika Dev

patika.dev

TechRepublic

techrepublic.com

SitePoint

sitepoint.com

Pragmatic Bookshelf

pragprog.com

Pressbooks

pressbooks.com

TechBeacon

techbeacon.com

AppSecEngineer

appsecengineer.com