Yea the internet was invented and started around 1991, so this is a prety huge breakthrough.

In the early 90s, "open" as in "open source" wasn’t yet a concept. There were projects like GNU, which were part of the Free Software movement. At that time, "open" meant something more like "no vendor lock-in." For instance, the Open Software Foundation (OSF) was an association of companies working together to combat Sun's monopoly on standards. It was only a few years later that "Open Source" began to emerge from the Free Software movement.