This book contains topics about Linux for developers as well as advanced users or administrators. The shells & commands together with expansion & substitutionare explained in detail. Process communication with pipes & redirection are explained. Scripting is covered for both developers and system experts at both fundamental and advanced level. Topics such as files, array, strings, declarations are added. Initialization scripts & crontab are explained. MySQL/MariaDB, PostgreSQL, MongoDB databases; Apache, NGINX, Tomcat web servers; C/C++, Java, JavaScript, Python development kits are included.