For this meetup, James Walker (walkah) is going to be presenting WebFinger / The Hammer Stack. This will be a fairly in-depth look at the various pieces that make up Hammer Discovery Protocol Stack (XRD, LRDD, /.well-known, etc) and how they fit together. I’ve spent some time looking at the big picture of this stuff, but have yet to dive into the minutiae, so I’m looking forward to this.

James works for StatusNet and is one of the authors of the OStatus 1.0 Draft.

There’s still plenty of space, so if you’re interested in discovery, or just want to chat about Open Web stuff, sign up on Guestlist. See you there!

Google have implemented an alpha of the WebFinger protocol. If you have a Google profile, click on “Edit your profile” and add ‘webfingeralpha’ as an interest. Congrats, your gmail address is now a WebFinger identifier and will resolve to an XRD file containing information about services you use (if you’ve included that information in your Google profile).

This is pretty fun to play around with. Given an email-like identifier, such as evalpaul@gmail.com, get the host-meta XRD file for the domain:

paul@knuth ~ $ curl -i http://gmail.com/.well-known/host-meta
HTTP/1.1 200 OK
Content-Type: application/xrd+xml
Transfer-Encoding: chunked
Date: Mon, 01 Feb 2010 12:36:47 GMT
Expires: Mon, 01 Feb 2010 12:36:47 GMT
Cache-Control: private, max-age=0
X-Content-Type-Options: nosniff
X-XSS-Protection: 0
X-Frame-Options: SAMEORIGIN
Server: GFE/2.0
...

<?xml version='1.0' encoding='UTF-8'?>
<!-- NOTE: this host-meta end-point is a pre-alpha work in progress.   Don't rely on it. -->
<!-- Please follow the list at http://groups.google.com/group/webfinger -->
<XRD xmlns='http://docs.oasis-open.org/ns/xri/xrd-1.0' 
     xmlns:hm='http://host-meta.net/xrd/1.0'>
  <hm:Host xmlns='http://host-meta.net/xrd/1.0'>gmail.com</hm:Host>
  <Link rel='lrdd' 
        template='http://www.google.com/s2/webfinger/?q={uri}'>
    <Title>Resource Descriptor</Title>
  </Link>
</XRD>

Now that you have the URI template, get the XRD file for the specific user:

curl "http://www.google.com/s2/webfinger/?q=acct%3Aevalpaul%40gmail.com"

<?xml version='1.0'?>
<XRD xmlns='http://docs.oasis-open.org/ns/xri/xrd-1.0'>
	<Subject>acct:evalpaul@gmail.com</Subject>
	<Alias>http://www.google.com/profiles/evalpaul</Alias>
	<Link rel='http://portablecontacts.net/spec/1.0' href='http://www-opensocial.googleusercontent.com/api/people/'/>
	<Link rel='http://webfinger.net/rel/profile-page' href='http://www.google.com/profiles/evalpaul' type='text/html'/>
	<Link rel='http://microformats.org/profile/hcard' href='http://www.google.com/profiles/evalpaul' type='text/html'/>
	<Link rel='http://gmpg.org/xfn/11' href='http://www.google.com/profiles/evalpaul' type='text/html'/>
	<Link rel='http://specs.openid.net/auth/2.0/provider' href='http://www.google.com/profiles/evalpaul'/>
	<Link rel='describedby' href='http://www.google.com/profiles/evalpaul' type='text/html'/>
	<Link rel='describedby' href='http://s2.googleusercontent.com/webfinger/?q=evalpaul%40gmail.com&amp;fmt=foaf' type='application/rdf+xml'/>
</XRD>

EDIT: Google have since rolled out WebFinger support for everyone with a Google Profile. You no longer need to add ‘webfingeralpha’ to your interests.

The workshop was fairly interactive with people from the audience asking questions or raising points every so often. It was a pretty diverse group professionally speaking, made up mostly of software developers, technologists, designers and some marketing people. The material wasn’t very technical, which I found disappointing, but given the crowd it was the only thing that made sense (I guess for some reason I expected more developers).

The real take-away of the workshop was an overview of various open standards and protocols that can be used together as a sort of Open Web stack. The usual suspects were discussed: OpenID, OAuth, PubSubHubub and a few that were fairly new to me: Portable Contacts, Activity Streams and the Salmon Protocol. Chris also spoke a bit about the Mozilla Drumbeat project which certainly looks interesting.

At the end of the workshop we got into groups and brainstormed about how social web technologies could be used to create a better web. I co-opted my group to talk about how FreshBooks (my employer) could be made more social. Some really interesting ideas were brought up and I think it’s a great case study for working with a community that already exists (as opposed to building a community for a new social application).

The workshop was great. I’m glad I had the opportunity to participate and I definitely came away with a few thoughts and ideas. For one, it could be a worthwhile project to document existing or create new open source projects that use open web technologies. Often it’s easy to find sample code, but it’s usually stripped down and not very useful. Real, concrete examples from open source projects could be extremely useful for developers looking to implement support for open technologies and protocols.