Teams developing operating systems
Canonical is the company behind Ubuntu, one of the world's most popular Linux distributions. They provide commercial support and services for Ubuntu and develop enterprise open source solutions.
Linux Foundation is an organization focused on developing open-source software, building communities and companies around the Open Source Software idea.
Red Hat (IBM subsidiary) is a Linux-oriented organization behind Fedora and RHEL. Office-flex policy allows working from home. WFH stipend and quarterly recharge days. 10,000+ employees.
SUSE is developing their main product. Open-source enterprise Linux distribution - SUSE Linux.