Hi gaussianum,
Well the sourcode has been released and hasn't... Actually, as Hasbro still owns the copyright for EAW, they didn't want to let the code in public but as they saw the giant mod-progress the EAW Community made, they gave the code to a small group of 5 people, whom were elected in a referendum of the EAW Community. See:
http://www.simhq.com/cgi-bin/ultimat...=000370#000000 and
http://www.simhq.com/cgi-bin/ultimat...=000261#000003
These guys are currently working on it. I've been out of EAW bussiness for almost a year now, so I don't know what is exactly going on there now.
So, because of the Hasbro's ownership, EAW isn't free. All the downloads and mods are, of course.
And I think EAW is still in stores somewhere. A few years back, I bought two copies of Italian EAW CD's in "Sale Books" store, 1 Euro each! Try lookin' for either shops like this one, PC Games Shops or the internet.
Cheers,
Pisis