[ about RealPlayer format]
and a pre-release open source player is available from https://player.helixcommunity.org/.
You've been tricked. That software is not open source or free software. It's an easy scam to fall for though, since they've made press releases which claim that the whole player is "open source" - a new low for RealNetworks IMHO.
The software at that site is released under a combination of 4 licenses, all quite long and newly written by RealNetworks. Both FSF and Debian have rejected all four.
The OpenSource team have certified *one* of those licenses as OpenSource - but that license only applies to parts of the interface, not the codec, so to use that player to view RealPlayer format videos, you must install the proprietary codec software too.
I mailed the JOLT@harvard people about a week before Ebens talk and asked that they make it available in a format which has a free software player - and they said they would. They made a previous talk (by Darl McBride) available in Speex format, but it took a few days extra so maybe if you check back to their speakers page in a few days, there will be a playable version.
In the mean time, a transcript of Ebens harvard talk is at: http://www.groklaw.net/article.php?story=20040226003735733
And here's an Ogg of a previous (better, IMO) talk by moglen: http://courses.durhamtech.edu/~jeremy/moglen/eben_moglen.ogg