I attended the panel on Open Source Infrastructure hosted by Marc Canter, Tantek Çelik,
Brian Dear, Matt Mullenweg and Toni Schneider.

Marc Canter coined the term "Open Source infrastructure" while pitching OurMedia to big companies while seeking funding. He pointed out that in the Web 2.0 world we are in danger of swapping the lock-in of desktop platforms controlled by big companies like Apple and Microsoft for lock-in of Web platforms controlled by big companies like eBay and Amazon. The same way we have open source platforms to prevent desktop lock-in, we need open source Web infrastructure to prevent platform lock-in.

Brian Dear of EVDB is working on making event publishing on the Web easier. Eventful is a website that aggregates events. The website is built on the EVDB API which is itself built on an the EVDB index over the EVDB Database. This same API is available for third parties to build applications against. Brian divides events into high definition and low definition events. Low definition events are easy to create and have simple metadata usually just a title and start/end time for the event. However simple events are hard to discover due to the lack of structured metadata. On the other hand, high definition events have lots of fields (title, start/end time, description, price, recurrence, etc) which makes them harder to create but easier to discover by applications.  They have created SES (simple event sharing) which is a mechanism for web sites to ping an event server with changes similar to how weblogs currently ping places like Weblogs.com and blo.gs when they are updated.  

At this point Marc Canter interjects and asks where the events are located. Will they be able to suck up events from sites like Craig's List or will they have to be on Eventful? Brian Dear states that he prefers the model where aggregators of events such as Eventful points to existing sites such as Craig's List especially since they are not metadata rich (i.e. low definition events). Marc then points to someone in the audience who has a similar site and asks whether they have a ping server model and he mentions that they crawl the Web instead.  

This segued into Matt Mullenweg talking about ping servers. Matt talked about ping-o-matic which aggregates ping servers so blogs can just ping it and it pings the dozens of ping servers out there instead. However they have significant scaling issues with some days where they get up to 4,000,000 pings a day. Unsurprisingly, a lot of the pings turn out to be spam. Matt has asked help from various sources and has gotten servers from Technorati. . Marc asks whether pings can grow beyond blogs to events, group creation and other types of pings. Although Matt seemed hesitant, Brian points out that they have extended the ping format already from what sites like Weblogs.com uses to accomodate their needs for events.

Yahoo! just bought upcoming which is an event site and Tony Schneider [who used to be at Oddpost] was representing Yahoo! on the panel. Tony believes that big companies shouldn't own the core services on the Web which is one of the motivations for Yahoo! opening up their APIs. The biggest develop communities around Yahoo!'s offerings come from the entities they have purchased such as Flickr & Konfabulator. Turning their services into developer platforms is now big at Yahoo!. Another thing that is really big at Yahoo! is using RSS. Yahoo! doesn't care that it isn't an official standard produced by a standard's body. It gets the job done. They are also acquiring core online services like blo.gs and keeping them open to benefit the developer world.  Marc asks when they decide when working with others (e.g. MediaRSS) versus buying companies (blo.gs and upcoming). Todd replies that with formats they first look at whether anything exists before creating something new (e.g. GeoRSS used in Yahoo! Maps API vs. MediaRSS which they created).

Tantek talked about Web 2.0 themes ('you control your own data', 'mix and match data', 'open, interoperable and web friendly data formats & protocols'). Marc points out that the Web is not the end all and be all so 'Web friendly' is cool but not overriding. Tantek also discussed Talked about microformat design principles and the various themes within the microformats community (open source tools, open communications and focus on concrete scenarios). He then briefly talked about two microformats. The first was hReview which is a format for reviews which got input from folks at Yahoo!, SixApart and MSN among others.  there are a lot of websites for reviews (Amazon, Yahoo! Local) but no real standard. The second was hReview which is now being used by http://www.avon.com to mark up the contact information for over 40,000 Avon representatives.  Tantek also shows that you can mark up the Web 2.0 speakers list and then he wrote a bookmarklet that can suck up all the speakers into his address book.

During the Q & A session I asked three questions 

1. Isn't the focus on centralized services for pinging worrying for services with lots of users because it is quite possible for us to overwhelm the services with our user base? Matt responded that this is why he was seeking donations from large companies. 
2. Currently microformats seem to be going fine since Tantek is the main guy creating them but what happens when others start creating them and unlike XML which has namespaces there is no way to disambiguate them? Tantek responded that there were already many people creating microformats. He also stated that the issue of duplicate or redundant microformats would be dealt with via the community process.
3. Isn't the big problem with the lack of adoption of standards for creating events, the lack of a killer app for consuming events? Tantek responded that the killer apps may be here already by showing how he wrote an app to consume hCalendar events and place them in his iCal calendar. Brian mentioned that Eventful uses hCalendar and hCard. 

In general, I'd have preferred if the panel was more of a discussion as opposed to an hour or more of sales pitches from the panelists with 10 minutes of Q & A at the end. I have a feeling that a lot more knowledge would have been gained by having members of the audience riff along with the panelists instead of the traditional "wisdom from above" model used in thuis panel.

An additional meta-comment about the conference is that so far I've been unable to get into 2 out of the 3 sessions I wanted to attend this morning because they were filled to overflowing. Given how much folks are paying for the conference and how much experience the O'Reilly folks have with holding conferences, one wouldn't see such problems occur.