red hat free software

debian is an operating system and a distribution of free software. it is maintained and updated through the work of many users who volunteer their time and effort.

q&a for ubuntu users and developers

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

linuxquestions.org offers a free linux forum where linux newbies can ask questions and linux experts can offer advice. topics include security, installation, networking and much more.

free, secure and fast downloads from the largest open source applications and software directory - sourceforge.net

the linux documentation project is workingtowards developing free, high quality documentation for the linux operatingsystem. the overall goal of the ldp is to collaborate in all of the issuesof linux documentation.