If we aren't using the same word processing software, it is very difficult to exchange files and read one another's work electronically. As a result, a single software package quickly becomes the standard, at least within your circle. Steel pens didn't have network effects. No one cared what kind of pen anyone else was using. And there was no need to have a standard.
Network effects have three implications for how competition works.
First, it tends to be competition for the market-competition to create the standard. Second, it tends to result in drastic innovation. Everyone knows they can't displace the standard with a small innovation. It has to be big-like going from steel pens to fountain pens. Third, the fragility of the winner's position depends on how likely drastic innovation is.