We gave birth to RIA.
Brad posted this a few months ago when JD @ Adobe got all fired up over Rich Interactive Applications vs Rich Internet Applications. Adobe will argue until they are blue in the face that Microsoft are attempting to Hijack the term RIA and .. blah blah blah.
Honestly, whom named RIA (Microsoft or Adobe) has become irrelevant. If you look at the history of RIA overall, it's something that we have always hinted at but never could quite get there.
VRML for example would have to by far my earliest memory of the "RIA" concept. You have a rich 3D world in which you can interact with, but of course in the late 1990's there was only so much you could do in terms of client-to-server side interaction.
In 2000, I remember seeing Erik's attempt at WebOS.com, which was by far the earliest iteration of RIA / AJAX I've seen. You may know of Erik today as one of the brains behind Google Gears, WebFX and Bindows.NET
I was working on Billabong's website's in 2000, when I first started to use Flash + Remote Servers, but it was with Flash 5 and all I could do was bring in variables remotely via PARAM or URL string. RIA was my intent but couldn't execute.
I've been on the Macromedia ride ever since, but like all the previous iterations of "RIA" it just hasn't been executed. There have been success stories of RIA working today, but it hasn't changed the landscape and I say this as if it has we wouldn't be seeing AJAX. There is no need for AJAX if "FLASH" RIA were to succeed? one cancels out the other and many have argued this case.
Silverlight and Flash Player are advanced, no question in this but both Adobe and Microsoft can't own RIA because it's realistically an idea or belief that was first formed many years ago and whilst Adobe will have you believe they are the founders of RIA, they simply built a campaign around it.
It's like saying AJAX is owned by Jesse James Garrett or he invented AJAX? (he did? I'm sure Google and Microsoft both had a large role to play in this, Microsoft with XmlHttpRequest and Google in its mainstream use).
We the community are the ones whom own RIA, not Microsoft or Adobe. They simply enable and market the idea of what RIA should be.