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

ubuntu is the modern, open source operating system on linux for the enterprise server, desktop, cloud, and iot.

q&a for computer enthusiasts and power users

q&a for system and network administrators

a help and support forum for ubuntu linux.

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.

github is where over 100 million developers shape the future of software, together. contribute to the open source community, manage your git repositories, review code like a pro, track bugs and features, power your ci/cd and devops workflows, and secure code before you commit it.

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

linux configuration tutorials