I'm going to respond to the thread of comments on the Growl/Zephyr/Jabber posts here, in the hopes that a regular post might help disseminate some of the information in related posts and comments.

Peter Millard, the author of Exodus wrote a post that addresses some of Mark Eichin's criticism of XMPP vs Zephyr. Peter and Mark, if you want to continue clarifying, etc, please feel free to use the comments on this post to do so. Peter was also somewhat put out because my criticism of Jabber clients was not concrete, which is true

Yesterday I asked Peter St. Andre if there was a scorecard comparing the features of the various Jabber clients. Here's why I asked that, and why (in part) my criticism of Jabber clients has been abstract. If you go to Jabber.org and look at "What is Jabber®?", you get a description that talks about open standards, some stuff about servers, security, and extensibility. What is missing, in my opinion, is a clear list of features that the Jabber/XMPP protocol enables, like "headlines". I want to see the client features (like headlines or security) that I don't get (or are hard to get) with other IM systems. Then I want to know which clients actually implement those features. From where I sit, it's very hard to know what is possible with Jabber/XMPP solutions, other than reading a stack of RFCS and JEPs. Unless I can tell people why I (and therefore they) are switching to Jabber, it's hard to make the case. The opening paragraph of the Jabber.org overview is about open standardsness. My own use of IM tells me that while I value open standards, I value features, and my network of people more. I use iChat, not because I love AOL (and I'm happy for whatever Jabber support Apple tosses into Tiger), but for one reason. It's the only client that I can use my iSight with, and the iSight video conferencing is the first web cam style thing that actually works for me. I'm starting to use Skype. I hate the proprietaryness of their protocol. But no one's audio sounds better (not even iChat), and nobody lets me do an n-way voice call. There are like 147 JEPs (okay less than that, but still a lot), most of which were presumably introduced to enable features. But beats the pants off of me if I could tell you what those features are.

I've been writing about Jabber because Lisa Dusseault and Joe Hildebrand tried to educate me one day. They sort of succeeded, because I know that there's a bunch of cool stuff that Jabber can do. But I don't really know what all that cool stuff is, and I have no idea whether a particular client can do the particular cool thing that I need. Jabber is a cool system, that can do cool stuff. I'm convinced of that (at least until Mark and Peter mix it up again). The problem is, I can't actually tell somebody else what any of the cool stuff is. I could read the pile of RFCs and JEPs and eventually figure it out. But it sure would help if someone who already knew could explain it for the rest of us.

Okay, so all that was abstract. Here's a concrete request. Which XMPP Macintosh client should I use if I want to experiment with headlines, so that I could do my system notifications with that instead of Growl?

Here's another one. All you Jabber folks come and leave a comment on your favorite cool - not found in any/most other IM systems - Jabber feature. I'm professing my ignorance -- here's your chance to educate me.

[ After I finished drafting this post, I discovered Dare's posting of the press release on MSN Spaces and the new MSN Messenger, and his personal favorite features. Those of us in the "free world" ought to be able to build stuff like this, and we need a substrate like XMPP to do it. ]

OSAF is looking for a server developer to work on WebDAV and (likely) CalDAV stuff. You'll probably be working on Slide, which means that the target language is Java, not Python.

Mark Eichin commented on the Growl vs Jabber post by reminding me about the Zephyr Notification service that we both used at MIT's Project Athena. Mark was one folks who worked on Zephyr (here's original paper -- danger, postscript file), so he was in a perfect position to point out some features that XMPP appears to lack (I haven't read all the RFC's). As Mark pointed out, this work is only 15 (actually I think it's more like 17 or 18 -- we were using the blasted thing before I graduated) years old. A few minutes of googling failed to turn up the source code for Zephyr, but did turn up the Jabber Windowgram Client. It also turns out that Adium can act a Zephyr client. I suppose it's somehow just desserts that I get reminded of history, and history that I had actually used, no less. Consider this post my penance. Additional slaps upside the head, er, factchecking welcomed.

I will point out that this isn't getting me closer to the thing I care about most: a single client that I can use to do IM, group chats, system notifications, voice, and video, and which will let me communicate with all the people I want to keep in touch with. Maybe in another 15 years?