Adobe HTTP streaming mechanism is the best approach if it works in your situation (either you can use their streaming server, another compatible one, such as Wowza, or use their tools to split video and place individual parts). This is better than RTMP when there are problems with the firewall. This is also better than Pseudo streaming, because the client-side code for processing individual parts is fully contained in the Flash player and it’s easier for you to implement and can provide a smoother result. In addition, since the player places the video together, you do not throw out the downloaded video when searching, as is often the case with pseudo-stream.
However, pseudo-streaming is still a very good option. This is almost the same as Adobe HTTP streams, but is implemented outside the player, and most often (but not necessarily) discards the downloaded video when searching outside the loaded section.
I can’t say for sure, but I suspect that the reason you don’t see much support for the Adobe HTTP streaming standard outside of Adobe products is because there are three completely different HTTP stream streams that do the exact same thing incompatible (Adobe, Apple, and Microsoft). If the three agree to some extent on the standard, third-party tool support should be easier to find.