For the longest time, I’ve avoided learning about Flash. When Flash was becoming popular for animations on web sites, it was mis-used and usually annoying. And all of the Flash-based ads are usually still annoying.
Some release of Red Hat Linux (4.1?) included RealEncoder and RealServer. Those were the basis for my first production use of RealVideo. Subsequently, after the Real/Red Hat bundling arrangement was discontinued, I bought a RealServer G2 license and used the Linux version (6.0.3.303) for my own purposes and for Comp Carnage.
I started working with streaming video at least 15 years ago. I still have souvenirs from before RealVideo, of Intel DVI and VivoActive. By the late 90s RealVideo seemed preeminent. It had been plausible to continue to think of RealVideo that way, even with the competition from Windows Media and QuickTime. But with the popularity of Flash Video, particularly with YouTube, but in many other places, it is hard to avoid the conclusion that Flash Video is now preeminent.