Publish/subscribe can be used for a lot more (see XEP-0163) but one of the most logical implementations to start with would be publish/subscribe as a rss-polling replacement. Right now a lot of people get updates for a website via an aggregator, this basically works by fetching an rss or atom file on a given interval and then parsing the result. Lets say your interval is 1 hour, then a worst case senario would be that you get the update 59 minutes later than it is published. A “solution” would be to set the interval to 1 minute. However this creates unessesarry bandwidth (and load) to the server.

For all this publish-subscribe seems to be the solution. The best way to see it is as a one-way chat. When a news items (or blog post or whatever) is post an item is published to a node. That node then sends out the notification to all subscribed clients. It is clean and simple (for a more in depth explanation you should read the XEP or google a bit!).

Now it would be awesome to see this implemented in some aggregator (especially Akregator since I am a kde-man), of course that would have to be done in such a way that I can use my existing JID (Jabber-ID) but that it does not appear online or receives other messages.

I think a good way to start is for me just to check-out the sources of Akregator, yet another project

I haven’t looked into it yet but it should be a fairly simple task to link from my foaf.rdf to my libre.fm rdf file.

Thanks to mpdscribble it is only 4 lines to scrobble to both last.fm and libre.fm!

The other more open project of the week is status.net. Open microblogging, and it is the software behind identi.ca. I have a personal setup which can also be used by the rest of the family (if they ever choce to) but which can communicate fine with other status.net instances.

A bridge to twitter has been setup so I can keep using that but just use my status.net clients. And one of the best features is that I can post and read posts via XMPP (Jabber)!.

After browsing trough the portage tree landed on jabberd2. It is writen in C (no java or whatever on my server!) and easy to setup. This basically means that I could register and login using kopete in no time!

Now the things I like about open protocols (and software of course) is that most of the times you can do way cooler things with it. Take the MSN (of Live) protocol for example: sending messages in plain text over the net! I prefer secure connections, all the time actually, and that is possible with jabber. It is even specified in the RFC. And not just my connection to my server, also the server2server connections are secure. I mean that is just awesome! Since I see no point in securing only one part of the route.

Now of course some of the people I chat with can still not use SSL which would mean kind of a security risk, and we do not want that. But since you can use a client of your liking I can also use OTR encryption while using jabber.

Now I already told you that jabber is open. Which means anyone with enough time (and some skills) can write a library for this protocol. Which in turn makes it easy to use for status messages of your bash scripts or for elog messages from portage! Now I have not checked on any of this but I could imaging jabber plugins for torrent/usenet deamons (informing you of your finished download) or even bootup messages from computers that you maintain informing you of several useful things!

Long story short. I like Jabber!

Edit: I am now using ejabberd (or recomandation of a fried) and the webinterface rocks!