Real Media Format
The RealNetworks format was one of the first true streaming solutions on the market. It was also one of the first major formats to offer multiple bitrate video with bandwidth detection which they branded as surestream. Their server platform was also the most advanced at the time. They offered full featured monitoring and a much more advanced user interface than any of the competitors at the time.
From an encoder standpoint they were also one of the first to offer push based broadcasting which allowed users that were behind routers or firewalls to stream without any special configuration or static ip addresses.
While it had a great start as a streaming media delivery method, many consider corporate greed as the downfall of this product. For one, the cost of the server licenses for hosts was very high especially in the early years. To add to this, in 1999 a security researcher discovered that the player was tracking the content the viewers were watching and reporting back to RealNetworks. RealNetworks later issued a patch that removed this but the player issues did not stop there. The player had a tendency to take over your media settings on your computer (including content that it couldn’t even play) as well as being full of advertisements and pop-ups.
The format still exists today and there are a few hosts remaining that still offer hosting for it but it is not really considered as an option for most people since viewers need to download a player that people are still afraid to download.