Normally, I like to stay out of these kinds of wars, but this post by Stu (whom I deeply respect and consider a friend, though he may not reciprocate by the time I'm done here) just really irked me somewhere sensitive. I'm not entirely sure why, but something about it just... rubbed me the wrong way, I guess is the best way to say it.
Let's dissect, shall we?
Stu begins with the following two candidates:
1. Joe has a problem to solve. The problem is specific, the need is immediate, and the scope is well-contrained.
2. Jane has a problem to solve. The problem is poorly understood, the need is ongoing, and the scope is ambiguous.
For starters, Joe doesn't exist. Or rather, exists only in the theoretical. Of course, neither does Jane really exist, either. Fact is, almost all projects are a combination of Joe and Jane. More importantly, Stu's efforts here to force people into the "either/or" approach to categorization is a subtle (or perhaps not so) ploy to force people into the decision-making path he thinks should be taken.
It's sort of like saying, most people fall into two categories:
- Joe lives in Ghettopia, where all the men are dumb, the women are ugly, and the children are rejects from the ADHD Clinic.
- Jane lives in Utopia, where all the men are smart, the woman are good-looking, and the children are well-behaved.
Think about it: you're at work, you have a project, and you happen across Stu's page. Faced with the typical project (too little time, too few resources, too vague in the understanding of requirements and domain comprehension), with whom are you likely to identify? Disturblingly happy Joe, who has a specific problem in a well-constrained scope? Hardly. So from the beginning, you're expected to identify with Jane, which (not surprisingly) leads you into Stu's preferred conclusion.
He goes on:
How should Joe and Jane think differently about software platforms?
1. Joe's platform needs to be mainstream. It needs to offer immediate productivity, and the toolset should closely match the problem. Also, Joe doesn't want to climb a learning curve.
2. Jane's needs are quite the opposite. Jane needs flexibility. She needs glue that doesn't set. She needs a way to control technical debt (Joe doesn't care.)
For my part, I am interested in Jane's problems. (And anyway, Joe often discovers he is actually Jane midway through projects.)
Hey, Stu, quick reality check for ya: most developers want all of the above. It's not a binary choice, productivity and toolset vs. flexibility and dynamism. The fact is, the Java language has a degree of flexibility, just not as much as is offered by the Ruby language. For that matter, if you want real flexibility, maybe you oughta look into Lisp, or even Smalltalk, since it (ST) can get at the underlying stack frames from the ST language itself! Now that's flexibility you Ruby guys can only dream of. (Oh, I know, Rubinius will give you that flexibility. Someday. Justin even alludes to how Rubinius is essentially an attempt to recapture that dynamism from Smalltalk. Ironic, then, isn't it, that the guys who wrote the fastest Smalltalk VM on the planet (Strongtalk, which is open-source now, by the way) ended up working at Sun... on the thing that later came to be called Hotspot? You think maybe they have a little familiarity and experience with VMs?)
And that crack about "control technical debt (Joe doesn't care)"?
Let me repeat that in case you missed it: BULL-SHIT.
Joe and Jane both care about technical debt. Each may be willing to spend their currency on different problems, granted, but both of them care about technical debt. Not caring about technical debt is what got Chandler into trouble, and it had nothing to do with language or tools whatsoever. It's insulting to suggest that either of them don't care about technical debt, particularly the guy that chooses differently than you.
(Shame on you, Stu. You know better. Quit trolling.)
So how does this affect platform choice? If you are Joe, you care about specific details about what a toolset can do right now. Most of Graeme's Top 10 reasons are in the "Right here, right now" category. This is true regardless of whether you think he is right. (Sometimes he is, sometimes not.)
I'll grant you, some of Graeme's Top 10 reasons are a bit spurious, and Stu-and-company do a good job of pointing those out. Frankly, anybody who makes a technical selection based on version numbers or whether or not a book exists for it seems to be missing the point, if you ask me. Of far greater concern is the stability of the language/tool, or the wealth of documentation for it. (And yes, this may seem to fly in the face of my arguments against Parrot a few posts ago; actually, it's not. If Parrot were more stable and/or more fully fleshed out, and the version updates just kept going, I'd be happy to say, "Go get this thing and give it a spin". But it doesn't feel stable to me, so I can't.)
But Stu's argument here is spurious: I don't care if you're Joe or if you're Jane, you always care about specific details about what a toolset can do, right now or otherwise. Certain concerns may be concerns that you can put off until later, but those concerns are always a part of the platform selection. Consider a hypothetical for a second: you currently are developing on Windows, and your project will run on Windows servers, with a possibility that it may need to run on non-Windows servers at some point in the future. Do you consider .NET or not? This is exactly the kind of detail that needs to be discussed--how likely is the move to a non-Windows server going to be? If it's <25%, then the CLR and ASP.NET might be a good choice, particularly if your developers are less "plumbing wonk" than "GUI designer", and you rely on being able to move the assemblies to a non-Windows server later via Mono.
Note: I'm not suggesting this a good choice in all scenarios. I'm making the point that the details of the toolset matter in your choice of toolsets, based on what your particular project needs are.
Jane cares just as much about toolset details as Joe does. I can't imagine a scenario where either of them don't care.
My advice to Joe: Know exactly what you need, and then pick the platform that comes closest to solving it out of the box. Depending on Joe's needs, either Rails or Grails might be appropriate (or neither!). A particular point in Grails' favor would be an established team of Spring ninjas.
"Know exactly what you need"? Ah, right, because Joe belongs to that .01% of projects that have "specific problems, immediate need, and well-constrained scope". Nothing like conceding a point to the other guys, in preparation for the "killer blow":
If you are Jane, you care more about architecture. I mean this term in two senses:
1. Architecture: the decisions you cannot unmake easily.
2. Architecture: the constraints on how you think and work.
If you are Jane, you care about how and why the platform was assembled, because you are likely to have to adapt it quite a bit.
You know, I don't think I've ever been on a project where I didn't care about architecture or in having to "adapt it quite a bit". Of course, back in the days when I was writing C++, this meant either subclassing CWnd or TWindow in interesting ways, or else sometimes even going so far as to reach into the source code and making some tweaks, either at compile-time or through some well-established hackery. (Yes, I wrote a template class called THackOMatic that allowed me to bang away on private fields. Sue me. It worked, I documented the hell out of it, and ripped the hack back out once the bug was fixed.) Point is, both Joe and Jane care about the architecture.
Now, I think what Stu means here is that the architecture of the web framework is more malleable in Rails than it is in Grails, because Rails is written on top of Ruby and Grails is written on top of Groovy, Spring, the JEE container architecture, and Java:
Most of the commenters on my earlier post (and Graeme in his addendum) correctly identified the real architectural difference between Grails and Rails. Rails builds on Ruby, while Grails builds on Groovy and Spring.
Yes! I agree with this so far. (In fact, everybody should, because these are simple statements of fact.) But then Stu takes the cake for the Best Parting Non-Supported Shot Ever:
Rails wins this architecture bakeoff twice:
* Ruby is a better language than Groovy.
* Spring does most of its heavy lifting in the stable layer, which is not the right place.
Ruby is perhaps a more flexible language than Groovy (and that's an arguable point, folks, and one which I really don't care to get into), but Ruby also runs on a less-flexible and less-scalable and less-supported platform than Groovy. I dunno that this makes Ruby better. It simply makes it different. Try convincing your IT guys to add yet another platform into their already-overwhelmingly complex suite of tools, particularly given the surprisingly sparse amount of monitoring information that Ruby platform offers. Stu may want to argue that Ruby-the-language is more flexible, regardless of what platform it runs on, and if so, then we're arguing languages not platforms, and while he might win much of his "Ruby is a better language than Groovy" argument, he's going to lose the "Ruby is more dynamic than Groovy", because on the JVM they have to be implemented under the same set of restrictions. You can't have it both ways.
(By the way, if you're one of those Ruby/Rails enthusiasts who's going to counterclaim that "Ruby-meaning-MRV is fast enough", I've heard the argument, and I think it's specious and ignorant. "Fast enough" is an argument that rests on your project being able to remain within the expected performance and scalability curve known at the beginning of the project, and remember, Jane's problem is that she doesn't know those sorts of things yet. So either you know, and have some better scope around the problem than Stu gives credit to Jane for having, or else you don't know, and can't assume that the Ruby interpreter will be able to handle the load.)
And WTF is up with the idea that "Spring does most of its heavy lifting in the stable layer, which is not the right place"? I think Stu means to say that Spring is a static layer, not stable layer, because hey, stability is kinda important to a few folks. (I'll give Stu the benefit of the doubt here and assume he cares about stability, too. I know his customers do.) Spring has its flaws, mind you, but arguing that it's not up to the heavy lifting seems to be like arguing that Java cannot scale. (Even Microsoft has given up on that argument, by the way.)
The worst part of this is, I've had discussions like this with Stu in the past, and he's much more articulate about it in person than he is in this blog post. Frankly, I think the most interesting space here is the intersection of Graeme's and Stu's positions, which is to say JRuby (and IronRuby or Ruby.NET, but that's for a different platform and out of the scope of this discussion entirely... yet still compelling and relevant, strangely enough). At the end of the day, these arguments about "my web framework is better than your web framework" are really just stupid. (As long as you're not trying to claim that Perl is the best web framework, anyway. Yes, Perl enthusiasts, I'm picking on you.)
My advice to Jane: Rails over Grails.
My advice to Jane: pick a consulting firm that doesn't have preconceived dogma about which web framework... or language, or any other toolset... to use. 
And if Jane can't afford a consulting firm, then Jane needs to do the research on her own and make her own decision based on the problem set, the context, and the whole range of tools available to her. (Anybody making a decision based solely on the basis of a blog-post-flame-war deserves what they get, regardless.)
As for Joe? Well, Joe could probably benefit from the goodness inherent in the dynamic languages that are popping up all over the place, too, not to mention the goodness inherent in the type-inferred languages that are starting to poke their heads through the Barrier of Adoption, all the while not ignoring the fact that he could probably benefit from the inherent performance and scalability of the major virtual machine technologies that have been a decade or more in production...
Meaning Joe probably needs to go through the same decision-making criteria Jane does. Thank God both of them, it turned out, work on the same project, as is often the case.
Meanwhile, I'm done with this thread. It's a pointless, stupid argument. Use the right tool for the job. Or, if you prefer, "From each language, according to its abilities, to each project, according to its needs."
Just remember that both shipping and supporting are features, too. Don't neglect the other in favor of the one.
 Yes, I saw the hyperlink to Ola's post about languages, and his definitions therein. Ironically, Ola's own comments there state that "Java is really the only choice here", which directly contradicts Stu's choice of MRV (the native Ruby interpreter). More importantly, I think Stu's point is resting on the static nature of the Java layer in Groovy, and while it's certainly more flexible to be able to hack at any layer of the stack, this is only realistically possible in small applications--this isn't my opinion, it's the opinion of Gregor Kiczales, who spent many years in CLOS and determined that CLOS's extremely flexible MOP system (more so than what Ruby currently supports, in fact) led to inherent problems in larger-scale projects. It was this thought that led him to create AspectJ in the first place.
 By the way, if there's any temptation in you to post commentary and say, "Dude, you just don't understand Ruby" or "How can you agree with Graeme this way?", just don't. I do understand Ruby, and I like the language. (Much more than I do Rails, anyway.) And I'm not intrinsically agreeing that Grails is better than Rails, because I don't believe that, either. I believe in the basic equation that says the solution you pick is the one that is the right solution to the given problem in the stated context that yields the most desirable consequences.
 This includes you, Stu. Or Justin, or Graeme, or anybody working for Relevance, or anybody working for G2One, Inc.