Tim Bray has a thorough essay on the pros and cons (mostly cons) of inventing new XML dialects.

Tim starts by saying…

Designing XML Languages is hard. It’s boring, political, time-consuming, unglamorous, irritating work. It always takes longer than you think it will, and when you’re finished, there’s always this feeling that you could have done more or should have done less or got some detail essentially wrong.

…. which pretty well sums up the challenges with creating new document formats for the Web. Of course, we try to eliminate some of these drawbacks when doing microformats- mostly be focusing on existing behaviors on the web and aiming for the 80% use case (rather than trying to satisfy every edge case), or in Tim’s words, “do[ing] less.”

As Tim went on to describe the challenges and pitfalls of creating arbitrary XML dialects, I was already preparing a “Just use microformats!” response in my head. But, alas, Tim beat me to the punch.

Along with DocBook, ODF, UBL and Atom, he recommends “XHTML+Microformats” as a way to reuse an existing XML dialect, and thereby bypass some of the birth pains of creating a new format. Tim says:

If you’re delivering information to humans over the Web, even if you don’t think of it as “Web Pages”, it’s almost certainly insane not to use XHTML. Yes, XHTML is semantically weak and doesn’t really grok hierarchy and has a bunch of other problems.

Thanks, Tim, for the endorsement of Microformats here.

Of course, the fact that the language is semantically weak, doesn’t seem like that big a deal to me, since we can build on top of the semantics it does have (instead of reinventing things like lists, links and paragraphs). And for hierarchies of things, you can always use XOXO.

Creating new XML languages is a hard task and not likely to be rewarding. We don’t need more arbitrary formats, each with their own namespace and slightly different semantics.

Just when you thought you wouldn’t have to read another “year in review” blog post…

2005 was an incredible year for the growth of microformats, in terms of specification, implementation, and overall awareness. The microformats.org community has produced some incredible results in just over six months of existence.

Simple microformats have found their way into several major search engines. Rel-license is indexed by both Yahoo and Google to help find content based on the page’s copyright giving another orthogonal key to search on. Vote-links showed their importance at the end of 2004 during the elections, and are indexed by Technorati to determine whether links from blogs are endorsements or not. Rel-tag and rel-directory are other simple microformats that have contributed to the building and indexing of folksonomies. XFN is now just over a two years old, and 2005 saw the emergence of the second (in addition to rubhub.com) XFN indexer and search engine: xhtmlfriends.net. XFN has seen a proliferation of uses throughout the web in 2005. Other simple microformats have been proposed, including one to determine when the last time a page was modified.

As for compound microformats, there have been three big ones that have been documented and have seen success. These are hCard, hCalendar, hReview. hReview is used to create reviews of movies, books, restaurants and many other things. Kritx.com indexes and aggregates hReviews and Yahoo UK uses them for their movie reviews. hCard is based on the vCard spec and has seen explosive growth this past year. Bloggers have used hCard to mark-up their contact information, but even more main-stream, Universities have marked-up their directories with hCards, Avon edited a single template and over 40,000 of their representative’s contact information is now easily machine readable. Eventful.com has published over 100,000 venues with hCards and even more events with hCalendar. hCalendar is a representation of iCalendar and allows for events to easily be extracted and imported into most calendaring programs. As bloggers talk about events and encode them in hCalendar, it allows events to be searched and aggregated across the entire web, as well as opening an RSS reader for news, today you might open an hCalendar reader to gather events. Eventful isn’t the only place to find hCalendar content, Upcoming.org, Laughing Squid and others all contribute to building a distributed calendar.

In 2005 several more compound microformats have begun, including hAtom and xFolk. hAtom allows you to encode a feed into your (X)HTML, so it is one and the same thing. xFolk is an open social bookmarking standard that would make it possible to easily collect social bookmark data and remix it to invent new services. Research is proceeding on a resume format, a citation microformat to describe publications, references, bibliographies, and a listing microformat to describe items for sale, for rent, or items people would like to buy.

As more and more companies add basic information about their business, search engines will be able to truly search based on more specific criteria such as zip code. Right now you search for “Pizza 63101” and that will return all search results that contain the term “pizza” in the “63101” zip code. Now with microformats you could limit the term “63101” to ONLY the postal-code property and “pizza” only to the FN,N,CATEGORY, or ORG property (that would stop all the buildings on “Pizza Street” from appearing in the results). Next, it would be possible to further restrict the restaurants to only those with associated hReviews of 3.5 stars or higher. Finally, if the site has encoded any information with hCalendar, you could determine their opening/closing hours any special deals and offers for a given day.

2005 has laid the groundwork for all of this to begin, as a community we should be proud of what we have done, and excited about where it is going. As microformats grow, 2006 and beyond look very exciting!

As you can see over to the right, the new events feed service stands ready to syndicate our calendar of upcoming events. The latest of which is an evening with the Emerging Tech SIG of SDForum to describe microformats and some of latest demos that are coming out of the woodwork.. Hope that some of you locals — and those of you in town for Macworld — can make it down to Palo Alto for the event. To ring in the New Year, CommerceNet has stepped up to host the meeting with free admission & free pizza!

Stephen Paul Weber has started a a blog about the XOXO microformat, different ways it can be used, and tools to do it with.

Check it out: the XOXO Blog.

A few weeks ago a few folks discovered the REST section of the microformats wiki, which discusses “how to optimally use Microformats as the encoding for REST web services”, but has grown to include broader discussions of applying microformats principles to both protocols and javascript techniques.

One of those principles could be rephrased as: Why use XML when (X)HTML will do?

Perhaps another could be rephrased: Why bother with parsing/transforming when you can just get the data in a presentable format? After all, we all know that less code is better.

AHAH (Asychronous HTML and HTTP) is the result of applying both of those principles to the incredibly Web 2.0 buzzworthy AJAX. Strictly speaking, AHAH is simply a subset of AJAX, albeit a subset that openly de-emphasizes the X in AJAX.

AJAX Magazine provided a good overview of the advantages of AHAH over “traditional” XML-based AJAX.

Keith Devens summarized it well:

…instead of grabbing arbitrary XML and processing it on the client-side with Javascript or XSLT and inserting things into the DOM, you just grab bits of (X)HTML from the server and inject them directly into your page. So, the client side does much less logic and merely needs to say “replace the content in the element with this ID with the (X)HTML at this URI

So if you’ve been wondering what this AJAX stuff is about, take a look at AHAH, you might find it gets you 90% of the hyped user interface advantages with only about 10% of the hype (and effort for that matter). That’s the kind of 90/10 rule we like around here.

But don’t take our word for it. See what others have been saying about AJAX and AHAH.