Welcome back to the blogoshpere! Great posts as usual.

I think you basically nailed it, but I tend to characterize things a bit differently. I completely agree the days of “one size fits all” are completely gone, and btw that’s why the concept of domain specific languages is so appealing.

I tend to think of the IT world as divided between systems designed before the Web, and those designed to include it. The mindsets are very different, as you point out, but I would add that the pre-Web mindset is kind of driven by mainframe centric designs – I like to think that the issues with existing middleware (and perhaps binary languages) is due to the fact we always felt we had to design in all the features/functions of mainframe based systems in order to entice enterprises to move those apps to standards based systems.

As you know the thinking behind the Web comes from an entirely diffent part of the software world. I believe the industry is starting to look at infrastructure behind the large Web sites as a kind of example of how things should be designed going forward. And I also think we are starting to see some software product designs based on these currently highly customized sites (this is the way a lot of the traditional middleware came to market too I believe, as vendors started productizing features/functions customers developed themselves when they couldn’t find products that met their requirements).

As you also say, it’s not possible to completely replace all the existing systems developed during the past 40 or so years of mainframe oriented thinking. I would suggest that implicit in your recommendation to do as much as possible based on HTTP is a recognition that we also need to build bridges into and out of these existing systems.

I did see at the end of your initial post this is your recommendation for when to use an ESB, so I am not arguing the point at all. Just trying to put a bit more emphasis on the idea that the corporate developers need help connecting up to the Web world.

Java works very well. It’s “write once run anywhere” mantra is true for the most part, especially now that dependency injection is becoming the norm. And how can you argue with zipping up your webapp as a war, dropping it into a webapps directory, and just watching it fire up? And really, if you want it, Java has a dynamic language and rails’ish environment too: Groovy and Grails. I’ve used both, they are great, and you can just drop a Grails app right into your webapps directory too. All of Grails DSLs are done in Groovy, so you can avoid XML hell, and I definitely agree XML hell is hell.

And why is it that whenever I see REST come up, it turns into an argument against compiled languages? The Java Restlet framework is awesome, and easy to get going. Grails also makes REST easy.

-Dustin

I did read all you post. I thought the ESB usage scenarios you mentioned were a little thin. and as I said in my post if you drop the presumption that the ESB will be the end-all solution you get a very usable piece of middleware

REST is not the end-all solution just as much as ESBs

Arnon