Which operating system is still used on some ISS systems today?

While most of us have long moved on from Windows XP, the International Space Station (ISS) hasn’t completely. Some critical onboard systems and laptops still run on this decades-old operating system. Why? Because XP is incredibly stable and many of the custom tools used by astronauts were built specifically for it. Updating software in space isn’t just risky — it can be life-threatening if something goes wrong. Until newer systems are fully tested and certified, XP continues to orbit Earth — silently, reliably.