For desktop or everything else. Because if its:

Web Servers, Supercomputers, Android Smartphones, Smart TVs, Network Routers, Network Switches, Embedded Devices, IoT Devices, NAS (Network-Attached Storage) Devices, Raspberry Pi, Smartwatches, Home Automation Devices, Google Chromebooks, Set-top Boxes, Drones, Digital Signage Devices, 3D Printers, Medical Devices, ATM Machines, Point of Sale (POS) Devices, Digital Cameras, Gaming Consoles, Virtual Private Servers (VPS), Automotive Infotainment Devices, Mainframes, Telecommunications Equipment, Scientific Research Equipment, Security Devices, Cloud Servers, Network Firewalls, Storage Area Networks (SAN), Enterprise Resource Planning (ERP) Devices, Customer Relationship Management (CRM) Devices, Big Data Analytics Devices, Machine Learning Devices, Artificial Intelligence Devices, Financial Trading Devices, Air Traffic Control Devices, Spacecraft Control Devices, Weather Forecasting Devices, Broadcast Automation Devices, Railway Signaling Devices, Electric Grid Control Devices, Smart Meters, E-Readers, Electric Vehicle (EV) Charging Stations, Robotics Devices

then Linux (or some kind of *Nix system) is probably what is running it. The only market share I dont see is desktop.