Glassfish OpenSSO instructions (where to download OpenSSO)?
You may want to try OpenAM.
I also noticed this.. http://download.java.net/general/opensso/webstartnew/ which will download the bits for testing. And guess what... there is an opensso.war and the like 'in there' that were produced about the same time as the tutorial was written.
As mentioned Go and see http://www.forgerock.com/ they provide support and downloads for OpenSSO as OpenAM
Video: http://www.youtube.com/watch?v=_o5ifx4euPw
Also http://www.axiomatics.com/ is a good replacement.
Seems when Oracle bought SUN the links from the open source projects got linked to nowhere. Finally I got it from http://www.oracle.com/technetwork/middleware/ias/downloads/101401-099957.html
Alternatively you can search on the oracle website for oracle_opensso_80U2.zip