red hat is the world’s leading provider of enterprise open source solutions, including high-performing linux, cloud, container, and kubernetes technologies.

sourceforge provides free & fast open source software downloads and development, and business software reviews and comparisons featuring the largest open source and business software directory.

q&a for ubuntu users and developers

openlogic delivers open source support and enterprise services for 400+ technologies. explore openlogic's open source solutions including technical support and lts.

tecmint - linux howtos, tutorials, guides, news, tips and tricks.

since 1983, developing the free unix style operating system gnu, so that computer users can have the freedom to share and improve the software they use.

stack overflow is the largest, most trusted online community for developers to learn, share​ ​their programming ​knowledge, and build their careers.

in-depth, to-the-point tutorials on java, spring, spring boot, security, and rest.