Axel Rietschin, kernel engineer at Microsoft, termed ReactOS “a ripoff of the Windows Research Kernel that Microsoft licensed to universities.”
Axel, a Senior Software Engineer (Windows Base Kernel, Container Technologies) wrote on Quora: “I think it’s a ripoff of the Windows Research Kernel that Microsoft licensed to universities under an agreement that was obviously violated by some, as the code has been uploaded to numerous places, some of it on GitHub.
“I glanced at the ReactOS code tree, and in my opinion, there is absolutely no way on Earth this was written from a clean sheet only from the available public documentation.”
For those uninformed, ReactOS is a free and open-source operating system, which according to the developers, was written from scratch. The UI and the overall look and feel of the OS will take to the Windows XP era, the OS looks quite similar to what XP and its predecessors looked like. It’s fast, supports almost all Windows application, and most importantly, it’s super tiny in size. ReactOS is a mere 127MB in size!
Axel suspects that ReactOS might be originated from one of the several leaks that happened in the past. “A more sinister scenario (given the amount of code beyond what can be readily found in a few minutes of Googling) would be that ReactOS originated from one of the several leaks that happened in the past,” he said.
“Now, I’m not a lawyer. Why this is allowed to exist I don’t know. Probably because it ends up being something like a baby mosquito on the back of a giant elephant.”
It’s also worth noting that even though you’re getting a classic Windows experience without a spending a buck, ReactOS is not illegal, meaning you can use it as your daily driver without any fear. You can download the ReactOS operating system from the official ReactOS site.