Guten Morgen!
Weil ich grade darüber am schreiben bin, mal wieder was zum Thema:
How I Explained REST to My Wife

Wife: Who is Roy Fielding?
Ryan: Some guy. He's smart.
Wife: Oh? What did he do?
Ryan: He helped write the first web servers and then did a ton of research explaining why the web works the way it does.
      His name is on the specification for the protocol that is used to get pages from servers to your browser.
Wife: How does it work?
Ryan: The web?
Wife: Yeah.
Ryan: Hmm. Well, it's all pretty amazing really. And the funny thing is that it's all very undervalued.
      The protocol I was talking about, HTTP, it's capable of all sorts of neat stuff that people ignore for some reason.
Wife: You mean http like the beginning of what I type into the browser?
Ryan: Yeah. That first part tells the browser what protocol to use.
      That stuff you type in there is one of the most important breakthroughs in the history of computing.
Wife: Why?
Ryan: Because it is capable of describing the location of something anywhere in the world from anywhere in the world.
      It's the foundation of the web. You can think of it like GPS coordinates for knowledge and information.
Wife: For web pages?
Ryan: For anything really. That guy, Roy Fielding, he talks a lot about what those things point to in that research
      I was talking about. The web is built on an architectural style called REST.
      REST provides a definition of a resource, which is what those things point to.
Wife: A web page is a resource?
Ryan: Kind of. A web page is a representation of a resource. Resources are just concepts. URLs--those things that you type into the browser...
Wife: I know what a URL is..
Ryan: Oh, right. Those tell the browser that there's a concept somewhere. A browser can then go ask for a specific representation of the concept.
      Specifically, the browser asks for the web page representation of the concept.
Wife: What other kinds of representations are there?
Ryan: Actually, representations is one of these things that doesn't get used a lot. In most cases, a resource has only a single representation.
      But we're hoping that representations will be used more in the future because there's a bunch of new formats popping up all over the place.
Wife: Like what?
Ryan: Hmm. Well, there's this concept that people are calling Web Services.
      It means a lot of different things to a lot of different people but the basic concept is that machines could use the web just like people do.
Wife: Is this another robot thing?
Ryan: No, not really. I don't mean that machines will be sitting down at the desk and browsing the web.
      But computers can use those same protocols to send messages back and forth to each other.
      We've been doing that for a long time but none of the techniques we use today work well when you need to be able to talk to all of the machines in the entire world.
Wife: Why not?
Ryan: Because they weren't designed to be used like that. When Fielding and his buddies started building the web,
      being able to talk to any machine anywhere in the world was a primary concern. Most of the techniques we use at work to get computers to talk to each other didn't have those requirements. You just needed to talk to a small group of machines.
Wife: And now you need to talk to all the machines?
Ryan: Yes - and more. We need to be able to talk to all machines about all the stuff that's on all the other machines.
      So we need some way of having one machine tell another machine about a resource that might be on yet another machine.
Wife: What?
Ryan: Let's say you're talking to your sister and she wants to borrow the sweeper or something. But you don't have it - your Mom has it.
      So you tell your sister to get it from your Mom instead. This happens all the time in real life and it happens all the time when machines start talking too.
Wife: So how do the machines tell each other where things are?
Ryan: The URL, of course. If everything that machines need to talk about has a corresponding URL, you've created the machine equivalent of a noun.
      That you and I and the rest of the world have agreed on talking about nouns in a certain way is pretty important, eh?
Wife: Yeah.
Ryan: Machines don't have a universal noun - that's why they suck. Every programming language, database, or other kind of system has a different way of talking about nouns.
      That's why the URL is so important. It let's all of these systems tell each other about each other's nouns.
Wife: But when I'm looking at a web page, I don't think of it like that.
Ryan: Nobody does. Except Fielding and handful of other people. That's why machines still suck.
Wife: What about verbs and pronouns and adjectives?
Ryan: Funny you asked because that's another big aspect of REST. Well, verbs are anyway.
Wife: I was just joking.
Ryan: It was a funny joke but it's actually not a joke at all. Verbs are important. There's a powerful concept in programming and CS theory called polymorphism. That's a geeky way of saying that different nouns can have the same verb applied to them.
Wife: I don't get it.
Ryan: Well.. Look at the coffee table. What are the nouns? Cup, tray, newspaper, remote. Now, what are some things you can do to all of these things?
Wife: I don't get it...
Ryan: You can get them, right? You can pick them up. You can knock them over. You can burn them. You can apply those same exact verbs to any of the objects sitting there.
Wife: Okay... so?
Ryan: Well, that's important. What if instead of me being able to say to you, "get the cup," and "get the newspaper," and "get the remote"; what if instead we needed to come up with different verbs for each of the nouns? I couldn't use the word "get" universally, but instead had to think up a new word for each verb/noun combination.
Wife: Wow! That's weird.
Ryan: Yes, it is. Our brains are somehow smart enough to know that the same verbs can be applied to many different nouns. Some verbs are more specific than others and apply only to a small set of nouns. For instance, I can't drive a cup and I can't drink a car. But some verbs are almost universal like GET, PUT, and DELETE.
Wife: You can't DELETE a cup.
Ryan: Well, okay, but you can throw it away. That was another joke, right?
Wife: Yeah.
Ryan: So anyway, HTTP--this protocol Fielding and his friends created--is all about applying verbs to nouns. For instance, when you go to a web page, the browser does an HTTP GET on the URL you type in and back comes a web page.
Web pages usually have images, right? Those are separate resources. The web page just specifies the URLs to the images and the browser goes and does more HTTP GETs on them until all the resources are obtained and the web page is displayed. But the important thing here is that very different kinds of nouns can be treated the same. Whether the noun is an image, text, video, an mp3, a slideshow, whatever. I can GET all of those things the same way given a URL.
Wife: Sounds like GET is a pretty important verb.
Ryan: It is. Especially when you're using a web browser because browsers pretty much just GET stuff. They don't do a lot of other types of interaction with resources. This is a problem because it has led many people to assume that HTTP is just for GETing. But HTTP is actually a general purpose protocol for applying verbs to nouns.
Wife: Cool. But I still don't see how this changes anything. What kinds of nouns and verbs do you want?
Ryan: Well the nouns are there but not in the right format.
Think about when you're browsing around amazon.com looking for things to buy me for Christmas. Imagine each of the products as being nouns. Now, if they were available in a representation that a machine could understand, you could do a lot of neat things.
Wife: Why can't a machine understand a normal web page?
Ryan: Because web pages are designed to be understood by people. A machine doesn't care about layout and styling. Machines basically just need the data. Ideally, every URL would have a human readable and a machine readable representation. When a machine GETs the resource, it will ask for the machine readable one. When a browser GETs a resource for a human, it will ask for the human readable one.
Wife: So people would have to make machine formats for all their pages?
Ryan: If it were valuable.
Look, we've been talking about this with a lot of abstraction. How about we take a real example. You're a teacher - at school I bet you have a big computer system, or three or four computer systems more likely, that let you manage students: what classes they're in, what grades they're getting, emergency contacts, information about the books you teach out of, etc. If the systems are web-based, then there's probably a URL for each of the nouns involved here: student, teacher, class, book, room, etc. Right now, getting the URL through the browser gives you a web page. If there were a machine readable representation for each URL, then it would be trivial to latch new tools onto the system because all of that information would be consumable in a standard way. It would also make it quite a bit easier for each of the systems to talk to each other. Or, you could build a state or country-wide system that was able to talk to each of the individual school systems to collect testing scores. The possibilities are endless.
Each of the systems would get information from each other using a simple HTTP GET. If one system needs to add something to another system, it would use an HTTP POST. If a system wants to update something in another system, it uses an HTTP PUT. The only thing left to figure out is what the data should look like.
Wife: So this is what you and all the computer people are working on now? Deciding what the data should look like?
Ryan: Sadly, no. Instead, the large majority are busy writing layers of complex specifications for doing this stuff in a different way that isn't nearly as useful or eloquent. Nouns aren't universal and verbs aren't polymorphic. We're throwing out decades of real field usage and proven technique and starting over with something that looks a lot like other systems that have failed in the past. We're using HTTP but only because it helps us talk to our network and security people less. We're trading simplicity for flashy tools and wizards.
Wife: Why?
Ryan: I have no idea.
Wife: Why don't you say something?
Ryan: Maybe I will.

Quelle: Ryan Tomayko’s Blog: How I Explained REST to My Wife
und hier mal ein Ausblick wie das ganze bei mir aussieht:

Nach meinen – zugegebenermaßen recht knappen – englischen Wünschen für das neue Jahr, hier noch einmal eine längere, deutsche Version:Ich habe vor ein paar Jahren bei einem Essen zum Jahreswechsel ein Geschichte überreicht bekommen. Lange Zeit lag sie in meinen Unterlagen (seltsamerweise behält man so etwas dann ja doch irgendwie, auch wenn man nie ganz genau weiß warum 🙂 ). Ich wollte die Geschichte immer mal weitergeben, war aber bislang zu bequem, den Text ab zu schreiben. So ergab es sich, dass sich eben diese Geschichte online fand. Da ich sicherlich ein oder anderen vergessen würde, und eigentlich alle Leute, die mich kennen die URL zu meiner Homepage haben, nehme ich mal einfach Abstand davon, das ganze per Email zu schicken und poste es einfach hier: 

Die Kupfermünze

Einmal habe ich eine Zeit lang in China gelebt. Ich war im Frühling in Shanghai angekommen, und die Hitze war mörderisch. Die Kanäle stanken zum Himmel, und immer war der ranzige, üble Geruch von Sojabohnenöl in der Luft. Ich konnte und konnte mich nicht eingewöhnen. Neben Wolkenkratzern lagen Lehmhütten, vor denen nackte Kinder im Schmutz spielten. Nachts zirpten die Zikaden im Garten und ließen mich nicht schlafen.Im Herbst kam der Taifun, und der Regen stand wie eine gläserne Wand vor den Fenstern. Ich hatte Heimweh nach Europa. Da war niemand, mit dem ich befreundet war und der sich darum kümmerte, wie mir zumute war. Ich kam mir ganz verloren vor in diesem Meer von fremden Gesichtern.Und dann kam Weihnachten. Ich wohnte bei Europäern, die chinesische Diener hatten.Der oberste von ihnen war der Koch; Ta-tse-fu, der große Herr der Küche. Er radebrechte deutsch und war der Dolmetsch zwischen mir und dem Zimmer-Kuli, dem Ofen-Kuli, dem Wäsche-Kuli und was es da sonst noch an Dienerschaft im Haus gab.Am Heiligen Abend, und ich saß wieder einmal verheult in meinem Zimmer, überreichte mir Ta-tse-fu ein Geschenk. Es war eine chinesische Kupfermünze mit einem Loch in der Mitte, und durch das Loch waren viele bunte Wollfäden gezogen und dann zu einem Zopf zusammengeflochten. “Ein sehr altes Münze”, sagte der Koch feierlich.”Und die Wollfäden gehört auch dir. Wollfäden sind von mir und mein Frau und von Zimmer-Kuli und sein Schwestern und von Eltern und Brüder von Ofen-Kuli – von uns allen sind die Wollfäden.”Ich bedankte mich sehr. Es war ein merkwürdiges Geschenk – und noch viel merkwürdiger, als ich zuerst dachte. Denn als ich die Münze mit ihrem bunten Wollzopf einem Bekannten zeigte, der seit Jahrzehnten in China lebte, erklärte er mir, was es damit für eine Bewandtnis hatte:Jeder Wollfaden war eine Stunde des Glücks.Der Koch war zu seinen Freunden gegangen und hatte sie gefragt: “Willst du von dem Glück, das dir für dein Leben vorausbestimmt ist, eine Stunde des Glücks abtreten?” Und Ofen-Kuli und Zimmer-Kuli und Wäsche-Kuli und ihre Verwandten hatten für mich, für die fremde Europäerin, einen Wollfaden gegeben als Zeichen, dass sie mir von ihrem eigenen Glück eine Stunde des Glücks schenkten.Es war ein großes Opfer, das sie brachten. Denn wenn sie auch bereit waren, auf eine Stunde ihres Glücks zu meinen Gunsten zu verzichten – es lag nicht in ihrer Macht, zu bestimmen, welche Stunde aus ihrem Leben es sein würde. Das Schicksal würde entscheiden, ob sie die Glücksstunde abtraten, in der ihnen ein reicher Verwandter sein Hab und Gut verschrieben hätte, oder ob es nur eine der vielen Stunden sein würde, in der sie glücklich beim Reiswein saßen; ob sie die Glücksstunde wegschenkten, in der das Auto, das sie sonst überfahren hätte, noch rechtzeitig bremste, oder die Stunde, in der das junge Mädchen vermählt worden wäre. Blindlings und doch mit weit offenen Augen machten sie mir, der Fremden, einen Teil ihres Lebens zum Geschenk.Nun ja – viele Chinesen sind abergläubisch. Aber ich habe nie wieder ein Weihnachtsgeschenk bekommen, das sich mit diesem hätte vergleichen lassen. Von diesem Tag an habe ich mich in China zu Hause gefühlt.Und die Münze mit dem bunten Wollzopf hat mich jahrelang begleitet. Ich habe sie nicht mehr. Eines Tages lernte ich jemanden kennen, der war noch übler dran als ich damals in Shanghai. Und da habe ich einen Wollfaden genommen, ihn zu den anderen Fäden dazugeknüpft – und habe die Münze weitergegeben.

(Joe Lederer, Von der Freundlichkeit der Menschen, München 1964)

Ich wünsche Euch allen

das Beste für das Jahr 2008!

Irgendwie ging 2007 viel zu schnell vorbei und eh man es sich versieht war das neue Jahr da! Ich hoffe, dass ich doch Zeit finden werde, den einen oder anderen mal wieder persönlich zu treffen – das hat sich ja im letzten Jahr nicht wirklich ergeben.