I just finished writing last month's Extreme XML column* entitled The XML Litmus Test: Understanding When and Why to Use XML. The article is a more formal write up from my weblog post The XML Litmus Test expanded to contain examples of appropriate and inappropriate uses of XML as well as with some of the criteria for choosing XML fleshed out. Below is an excerpt from the article which contains the core bits that I hope everyone who reads it remembers  

XML is the appropriate tool for the job if the following criteria are satisfied by choosing XML as the data representation format for a given application.

1.      there is a need to interoperate across multiple software platforms

2.      one or more of the off-the-shelf tools for dealing with XML can be leveraged when producing or consuming the data

3.      parsing performance is not critical

4.      the content is not primarily binary content such as a music or image file

5.      the content does not contain control characters or any other characters that are illegal in XML

If the expected usage scenario does not satisfy most or all of the above criteria then it doesn't make much sense to use XML as the data representation format for the situation in question.

As the program manager responsible for XML programming models and schema validation in the .NET Framework I've seen lots and lots of inappropriate usage of XML both from internal teams and our customers. Hopefully once this article is published I can stop repeating myself and just send people links to it next time I see someone asking how to escape control characters in XML or see another online discussion of "binary" XML.

* Yes, it's late


Categories: XML

A few days ago I saw the article Xamlon looks to beat Microsoft to the punch  on C|Net which begins

On Monday, Colton's company Xamlon released its first product, a software development kit designed to speed development of user interface software for Web applications. Xamlon built the program from the published technical specifications of Microsoft's own user interface development software, which Microsoft itself doesn't plan to release until 2006.

I've been having difficulty processing this news over the past few days. Reading the Xamlon homepage gives more cause for pause. The site proclaims

XAML is a revolution in Windows application development. Xamlon is XAML today.

  • Rapidly build Windows user interfaces with HTML-like markup
  • Easily draw user interfaces and convert directly to XAML
  • Deploy to the Windows desktop and to Internet Explorer with absolutely no changes to your application.
  • Run XAML applications on versions of Windows from ’98 to Longhorn, and via the Web with Internet Explorer
  • Write applications that port easily to Avalon

What I find interesting about this are the claims that involve unreleased products that aren't expected to beta until next year and ship the year afterwards. I can understand that it is cool to claim to have scooped Microsoft but considering that the XAML and Longhorn are still being worked on it seems strange to claim to have built a product that is compatible with unreleased Microsoft products.

While writing this blog entry I decided to take a quick glance at the various Avalon folks' blogs and I stumbled on a post entitled Attribute grammar for xaml attributes from Rob Relyea, a program manager on the Avalon team.  Rob writes

As part of this change, the flexibility that people have with compact syntax will be reduced.  Today, they can use *Bind(), *Button(), *AnyClass() in any attribute.  We'd like to restict this to a small set of classes that are explicitly in need of being set in an attribute.

I'm not going into great detail in the description of our fix because I'd prefer to be the first company to ship our design.  :-)

Considering that XAML isn't even in beta yet, one can expect a lot more changes to the language before it ships in 2006. Yet Xamlon claims to be compatible with XAML. I have no idea how the Xamlon team plans to make good on their promise to be compatible with XAML and Longhorn before they've even shipped but I'd love to see what developers out there think about this topic.

I totally empathize with the Avalon team right now. I'm in the process of drafting a blog post about the changes to System.Xml of the .NET Framework that have occured between Whidbey beta 1 and Whidbey beta 2. Even though we don't have companies building products based on interim versions of System.Xml we do have book authors who'll have to rewrite [or maybe even eliminate] chapters about our stuff based on changes then off course there's the Mono folks implementing System.Xml who seem to be tracking our Whidbey betas.  


I've been trying to come up with a list of the most disappointing movie sequels or prequels of all time. So far I've come up with three the got stuck.

  1. Phantom Menace, prequel to the Star Wars Trilogy
  2. Matrix Revolutions, sequel to Matrix Reloaded
  3. Escape from LA, sequel to Escape from NY

I'm curious as to what suggestions others have for filling out this list. There is one rule that has to be obeyed in submitting entries to this list. Sequels that went straight-to-video do not count. So the various Disney sequels to their major hits like Aladdin or Beauty & the Beast don't count nor do movies like Cruel Intentions 3 or Children of the Corn 7.

So which are your nominees for most disappointing movie sequel?


Categories: Ramblings

October 8, 2004
@ 05:58 PM

In his post Debating WS-* Geoff Arnold writes

Tim Bray continues to discuss the relevance of the so-called WS-* stack: the collection of specifications related to XML-based web services. I'm not going to dive into the technology or business issues here; however Tim referred to a piece by Dare Obasanjo which argues that WS-* Specs are like JSRs. I tried to add a comment to this, but Dare's blog engine collapsed in a mess of XML, so I'll just post it here. Hopefully you'll be able to get back to read the original piece if you're interested. [Update: It looks as if my comment made it into Dare's blog after all.]

Just out of curiosity... if WS-* are like JSRs, what's the equivalent of the JCP? Where's the process documented, and what's the governance model? The statement "A JSR is basically a way for various Java vendors to standardize on a mechanism for solving a particular customer problem" ignores the fact that it's not just any old "way"; it's a particular "way" that has been publically codified, ratified by the community, and evolved to meet the needs of participants.

Microsoft isn't trying to compete with standards organizations. The JCP process falls out of the fact that Sun decided not to submit Java to a standards body but got pushback from customers and other Java vendors for something similar. So Sun manufactured an organization and process quite similar to a standards body with itself at the head. Microsoft isn't trying to get into this game.

The WS-* strategy that Microsoft is pursuing is informed from a lot of experience in the world of XML and standards. In the early days of XML, the approach to designing XML standards [especially at the W3C] was to throw together a bunch of preliminary ideas and competing draft specs without implementation experience then try to merge that into a coherent whole. This has been problematic as I wrote a few months ago

In recent times the way the W3C produces a spec is to either hold a workshop where different entities can submit proposals and then form a working group based on coming up with a unification of the various proposals or forming a working group to find come up with a unification of various W3C Notes  submitted by member companies. Either way the primary mechanism the W3C uses to produce technology specs is to take a bunch of contradictory and conflictiong proposals then have a bunch of career bureaucrats try to find some compromise that is a union of all the submitted specs. There are two things that fall out of this process. The first is that the process takes a long time, for example the XML Query workshop was in 1998 and six years later the XQuery spec is still a working draft. Also XInclude proposal was originally submitted to the W3C in 1999 but five years later it is just a candidate recommendation. Secondly, the specs that are produced tend to be too complex yet minimally functionaly since they compromise between too many wildly differing proposals. For example, W3C XML Schema was created by unifying the ideas behind DCD, DDML, SOX, and XDR. This has lead to a dysfunctional specification that is too complex for the simple scenarios and nigh impossible to use in defining complex XML vocabularies.

The WS-* process Microsoft has engaged the industry in aims at preventing this problems from crippling the world of XML Web Services as it has the XML world. Initial specs are written by the vendors planning who'll primarily be implementing the functionality then they are revised based on the results of various feedback and interoperability workshops. As a result of these workshops some specs are updated while others turn out to be infeasible and are deprecated. Some people such as Simon Fell, in his post WS-Gone, have complained that these leads to a situation where things are too much in flux but I think this is a lot better than publishing standards which turn out to contain features that are either infeasible to implement or are just plain wrong. Working in the world of XML technologies over the past three years I've seen both.

The intention is that eventually the specs that show that they are the fittest will end up in the standards process. This exactly what has happened with WS-Security (OASIS) and WS-Addressing (W3C). I expect more to follow in the future.


Categories: Technology | XML

In his post What is the platform? Adam Bosworth writes

When I was at Microsoft, the prevailing internal assumption was that:
1) Platforms were great because they were "black holes" meaning that the more functionality they had, the more they sucked in users and the more users they had the more functionality they sucked in and so, it was a virtuous cycle.
The real value in my opinion has moved from the software to the information and the community. Amazon connects you to books, movies, and so on. eBay connects you to goodness knows how many willing sellers of specific goods. Google connects you to information and dispensers of goods and services. In every case, the push is for better and more timely access both to information and to people. I cannot, for the life of me, see how Longhorn or Avalon or even Indigo help one little bit in this value chain.

My mother never complains that she needs a better client for Amazon. Instead, her interest is in better community tools, better book lists, easier ways to see the book lists, more trust in the reviewers, librarian discussions since she is a librarian, and so on.

The platform of this decade isn't going to be around controlling hardware resources and rich UI. Nor do I think you're going to be able to charge for the platform per se. Instead, it is going to be around access to community, collaboration, and content. And it is going to be mass market in the way that the web is mass market, in the way that the iPod is mass market, in the way that a TV is mass market. Which means I think that it is going to be around services, not around boxes.

Last week while hanging out with Mike Vernal and a couple of smart folks from around Microsoft I had an epiphany about how the core of the consumer computing experience of the future would be tied to Web-based social software not operating systems and development platforms. When I read Adam Bosworth's post this weekend, it became clear to me that folks at Google have come to the same conclusion or soon will once Adam is done with them.

So where do we begin? It seems prudent to provide my definition of social software so we are all on the same page. Social software is any software that enables people to interact with one another. To me there are five broad classes of social software. There is software that enables 

  1. Communication (IM, Email, SMS, etc)
  2. Experience Sharing (Blogs, Photo albums, shared link libraries such as del.icio.us)
  3. Discovery of Old and New Contacts (Classmates.com, online personals such as Match.com, social networking sites such as Friendster, etc)
  4. Relationship Management (Orkut, Friendster, etc)
  5. Collaborative or Competitive Gaming (MMORPGs, online versions of traditional games such as Chess & Checkers, team-based or free-for-all First Person Shooters, etc)

Interacting with the aforementioned forms of software is the bulk of the computing experience for a large number of computer users especially the younger generation (teens and people in their early twenties). The major opportunity in this space is that no one has yet created a cohesive experience that ties together the five major classes of social software. Instead the space is currently fragmented. Google definitely realizes this opportunity and is aggressively pursuing entering these areas as is evidenced by their foray into GMail, Blogger, Orkut, Picasa, and most recently Google Groups 2. However Google has so far shown an inability to tie these together into a cohesive and thus "sticky" experience. On the other hand Yahoo! has been better at creating a more integrated experience and thus a better online one-stop-shop (aka portal) but has been cautious in venturing into the newer avenues in social software such as blogs or social networking. And then there's MSN and AOL.

One thing Adam fails to mention in his post is that the stickiness of a platform is directly related to how tightly it holds on to a users data. Some people refer to this as lock-in. Many people will admit that the reason they can not migrate from a platform is due to the fact that they have data tied to that platform they do not want to give up. For the most part on Windows, this has been local documents in the various Microsoft Office formats. The same goes for database products, data tends to outlive the application that was originally designed to process it nine times out of ten. This is one of the reasons Object Oriented Databases failed, they were too tightly coupled to applications as well as programming languages and development platforms. The recent push for DRM in music formats is also another way people are beginning to get locked in. I know at least one person who's decided he won't change his iPod because he doesn't want to loose his library of AAC encoded music purchased via the iTunes Music Store.

The interesting thing about the rise of social software is that this data lock-in is migrating from local machines to various servers on the World Wide Web. At first the battle for the dominant  social software platform will seem like a battle amongst online portals. However this has an interesting side effect to popular operating systems platforms. If the bulk of a computer user's computing experience is tied to the World Wide Web then the kind of computer or operating system the browser is running on tends to be irrelevant.

Of course, there are other activities that one performs on a computer such as creating business documents such as spreadsheets or presentations and listening to music. However most of these are not consumer activities and even then a lot of these are becoming commodified. Music already has MP3s which are supported on every platform. Lock-in based on office document formats can't last forever and I suspect that within the next five more years it will cease to be relevant. This is not to say that all people need is a web browser for all their computing needs but considering how much most people's computer interaction is tied to the Internet, it seems likely that owning the user's online experience will one day be as valuable as owning the operating system the user's Web browser is running on. Maybe more so if operating systems become commodified thanks to the efforts of people like Linus Torvalds.

This foray by Google into building the social software platform is definitely an interesting challenge to Microsoft both in the short term (MSN) and in the long term (Windows). This should be fun to watch.


Categories: Technology

Looking at the monthly download statistics for RSS Bandit I see that there were over 20,000 downloads for the month of September and we've hit over 100,000 total downloads [across all versions] since the project moved to SourceForge last December.

Thanks to everyone out there using RSS Bandit especially those who've been providing us feedback on how to make it an even better aggregator. You guys rock.

If you are a new user don't forget to read the RSS Bandit Product Roadmap and tell us what you think.


Categories: RSS Bandit

In recent times I've been pitching the concept of a digital information hub to various folks at work.  Currently people have multiple aplications for viewing and authoring messages. There are instant messengers, email clients, USENET news readers and RSS/Atom aggregators. All of these applications basically do the same thing; provide a user interface for authoring and viewing messages sent by one or more people to the user.

Currently the split has been based on what wire protocol is used to send and receive the messages. This is a fairly arbitrary distinction which means little to non-technical users. The more interesting distinction is usage patterns. For all of the aforementioned application types messages really fall into two groups; messages I definitely will  read and messages I might want to read. In Outlook, I have messages sent directly to me which I'll definitely read and messages on various discussion lists I am on [such as XML-DEV] which I might want to read if the titles seem interesting or relvant to me. In Outlook Express, there are newsgroups where I read every message and others where I skim content looking for titles that are of interest or are relevant to me. In RSS Bandit, there are feeds where I read every single post (such as Don's or Joshua's blogs) and those where I skim them looking for headlines (e.g. Blogs @ MSDN). The list goes on...

The plan I've had for RSS Bandit for a while has been to see if I can evolve it into the single application where I manage all messages sent to me. Adding NNTP support is a first step in this direction. Recently I realized that some other folks have realized the power of the digital information hub; Google.

However Google has decided to bring the mountain to Mohammed. Instead of building an application that manages messages sent via all the different protocols in a single application they've decided to expose the major classes of messages as Atom feeds. They already provide Atom feeds for weblogs hosted on Blogger. Recently they've experimented with Atom feeds for USENET groups as well as Atom feeds for your GMail account. This means instead of one application being your digital information hub, any Atom savvy client (such as RSS Bandit) can now hold this honor if you use Google as your online content provider.

This is very, very interesting. I'm beginning to really like Google.


Categories: RSS Bandit | Technology

In a recent post on James Robertson's blog entitled Re: This is interesting he wrote

In this post, I was stunned by the notion that an air traffic control system might be on win 95/98. Commenters pointed out this link, which indicates that the more likely explanation is this:

The elapsed time is stored as a DWORD value. Therefore, the time will wrap around to zero if the system is run continuously for 49.7 days.

This is just too amusing for words. A multi-hour shutdown caused by static typing, and the fact that many typing decisions in languages that require it end up being essentially random. Note to static typing advocates - had they used Smalltalk, this kind of problem would be impossible....

As pointed out by several of the comments in his post the problem had nothing to do with static typing versus dynamic typing. Instead the problem is that when the type overflows instead of erroring it simply wraps around. Whether the name of the type is known at compile time or not (i.e. static typing) really doesn't come into the question.

James Robertson is a Smalltalk advocate and just like every other advocate of a niche programming language (e.g. Lisp advocates)  he spends lots of time ranting about how every problem that exists in programming languages today was solved 20 years ago in his language of choice. The main problem with James's post isn't that he incorrectly judged the root of the issue.

The main problem with his post is that even though many people corrected his error, he has stubbornly stuck to his guns. Now instead of just seeming like he made a mistake which was pointed out by his readers he now looks like he either (a) twists issues to fit his agenda regardless of the truth or (b) is unknowledgeable of the topics he is trying to argue about.

If you are trying to convince people to come to your side in a technical discussion, refusing to admit flaws in your arguments is more likely to lose you supporters than gain them. Stubbornly sticking to your guns after being shown the error of your ways may work for the Bush administration when it comes to the War on Iraq but it doesn't win you many technical debates.


Categories: Ramblings

October 3, 2004
@ 06:38 PM

As an author of a news reader that supports RSS and Atom, I often have to deal with feeds that are often technically valid RSS/Atom feeds but for one or more reasons cause unnecessary inconvenience to authors and users of news aggregators. This is the second in a series of posts highlighting such feeds as an example to others on how not to design syndication feeds for a website.

This week's gem is the Sun Bloggers RSS feed. This RSS feed is a combined feed for all the blogs hosted at http://blogs.sun.com. This means that at any given time the feed most likely contains posts by multiple authors.

To highlight the problem with the feed I present the following two item elements taken from the feed a few minutes ago.

    <title>Something fishy...</title>
    <description>A king was very fond of fish products. He went fishing in the only river of his kingdom. While fishing he accidently dropped his diamond ring presented by his wife - The Queen. A fish in the river mistook the sparkling ring for an insect and swallowed it. The fisherman caught the fish and sold it to a chef. The King on the other side was very sad and apologistic. Took the Queen to a restaurant for a dinner and ordered a fried fish. The chef presented the same which had the diamond ring inside. King was happy to find the ring back and rewarded the restaurant. The restaurant rewarded the chef and the Chef rewarded the fisherman. The fisherman then went back to the river, killed all the fishes in search of another diamond ring. I never understood the motto of the story but there is certainly something fishy about it!</description>
    <guid isPermaLink="true">http://blogs.sun.com/roller/page/ashish/20041002#something_fishy</guid>
    <pubDate>Sat, 2 Oct 2004 08:53:15 PDT</pubDate>
    <title>Another one bytes the dust...</title>
    <description>Well, more like another one got bitten. Accoring to &lt;a href="http://www.heise.de/newsticker/meldung/51749"&gt;this&lt;/a&gt; (german) article from &lt;a href="http://www.heise.de"&gt;Heise&lt;/a&gt; Mr. Gates got himself some Spyware on his personal/private systems, and has now decided to take things into his own hand (or at least into those of his many and skilled engineers). Bravo!&lt;p&gt; Spyware or other unwanted executables like e.g. &lt;a href="http://securityresponse.symantec.com/avcenter/expanded_threats/dialers/"&gt;dialers&lt;/a&gt; are puzzeling me for some time now, since I simply don't understand how those thinks can be kept legal at all. No one needs dialers. There are enough good ways for online payment. No one in their right mind can honestly belive, that anyone with a serious business would need any of that crap. It's a plain ripoff scheme.&lt;p&gt;</description>
    <guid isPermaLink="true">http://blogs.sun.com/roller/page/lars/20041002#another_one_bytes_the_dust</guid>
    <pubDate>Sat, 2 Oct 2004 07:32:18 PDT</pubDate>

The problem with the feed is that even though the RSS 2.0 specification has a provision for an author element and the Dublin Core RSS module has the dc:creator element which can be used in its stead the Sun Bloggers RSS feed eschews directly identifying the author of the post in the feed. 

The obvious benefits of identifying authors in collaborative feeds include enabling the reader to better determine whether the speaker is an authority on the topic at hand or begin to ascribe authority to the author if the reader was previously unaware of the author. Then there are aggregator specific benefits such as the fact that readers could then group or filter items in the feed based on the author thus improving their reading experience.  

A solution to this problem is for the webmaster of the Sun Bloggers site to begin to use author elements to identify the authors of the various posts in the Sun Bloggers feed.


October 3, 2004
@ 06:10 PM

I just came up on some invites for Wallop a couple of days ago but have been too busy with work to explore it so far. I have about half a dozen invites to give away but don't have any friends who I think would use the system enough to give Lili and co the sort of feedback they want for their research project. If you are a friend of mine who would be interested in exploring and using Wallop then ping me over email or respond to this blog posting.

By the way if you are curious about what Wallop is, the quick description of the project is

is a research project of the Social Computing Group at Microsoft Research, exploring how people share media and build conversations in the context of social networks. 

With any luck I'll get a chance to explore Wallop over the next few days and perhaps will post my thoughts on how the experience compares to other online communities targetted at the same niche.