Gregory's Server@RetroFunPL I think I'd agree on that being most likely a Java app. But also, based on the font rendering, ui colors, and titlebar, it doesn't appear to be running on Windows at all. Probably some sort of Unix, given the timeframe and companies involved. Possible (but unlikely) to be Linux.
@kepstin now, I'm actually intrigued how often is Unix more likely than a Linux in companies (maxOS excluded)