Why Do Most Servers Run Linux? Expert Answers and Historical Analysis

Recently the author collected a series of Zhihu answers to the question “Why are most servers using Linux?” and presents the diverse reasons given by different contributors.

Early Windows/IIS era – About 20 years ago, Windows Server + IIS + ASP + Access was popular for low‑traffic small‑business sites. Examples include the Chinese “动网论坛” built with ASP + Access, later evolving to “动网先锋” and “动网新闻”. ASP.NET raised costs, while PHPWIND (Zend‑based) rose quickly. Virtual‑host providers often bundled “动易组件” with Windows hosts and Zend with Linux hosts, leading to security issues such as exposed data.mdb files that could be downloaded and read in plain text.

IIS’s decline – Initially IIS had advantages: built‑in FTP and ASP required no extra deployment, and a GUI suited novice admins. However, its closed ecosystem hurt support for languages like PHP, Ruby, and others. Performance was far behind Apache, Nginx and Lighttpd, which use poll/epoll and achieve several times higher concurrency. Complex configuration and difficult debugging further pushed users toward Linux‑based web servers.

Game‑server experience – The author tried setting up a Windows Server for a game (帕鲁) and faced missing VC and DirectX runtimes, making installation cumbersome. Switching to Ubuntu allowed a simple apt install steamcmd and running server.sh. For lightweight scenarios (e.g., 2‑4 CPU, 2‑4 GB RAM), Windows struggled, while Linux handled them efficiently.

Licensing cost – Windows Server is priced per CPU core, costing roughly ¥100,000 for a licensed server, whereas Linux is free.

Infrastructure perspective – A professional infrastructure developer highlights Linux’s ecosystem dominance (most developers use it, so tools and libraries gravitate there), its lightweight distributions (e.g., Alpine) that enable minimal‑size containers, and native container support that Windows and macOS lack, making Linux the preferred platform for modern container‑centric deployments.

Microsoft’s historical stance on open source – In the early 2000s Microsoft opposed open‑source software; Bill Gates’s public letter criticized hobbyists using unlicensed software. Microsoft’s revenue relied on Windows and Office, and its business model expected payment for software use. Meanwhile, the open‑source community, especially academia, grew rapidly, fostering a vibrant ecosystem that eventually forced Microsoft to embrace open source.

Matthew‑effect observation – One contributor warns against attributing outcomes to single causes. The dominance of Linux today results from a self‑reinforcing cycle: a mature, free, Unix‑compatible kernel appeared in 1991, quickly built a rich ecosystem, and became the default skill for sysadmins, whereas Windows Server (NT) arrived later (1993) and never achieved comparable market share.

Overall, the collected answers explain that Linux’s prevalence on servers stems from historical timing, open‑source ecosystem growth, superior performance and container support, lower cost, and the gradual decline of Windows/IIS due to its closed nature and higher licensing fees.