I think that's part of the problem, but only a part of the problem. One of the things I think we're slowly groping towards is the importance of composability i

I think that's part of the problem, but only a part of the problem. One of the things I think we're slowly groping towards is the importance of composability in all sorts of programs. The problem is, where we'd like to write "app1 <> app2" and have the result be something sensible (as in monoidal composition in something like Haskell), the problem is that we don't have a well defined definition of "composing" two applications together when those applications each have their own page layout, HTML widgets, style sheet, data persistence, user authentication model, user authorization model, server communication methods, URL scheme, configuration information, and who knows what else I'm forgetting. I was reminded of something like this today as I'm sitting here slicing an application up into bits, and I realized I was basically implementing a composition system for the bits of my app, but the composition of "a thing that has some HTTP handlers, and some data types, and some methods, and some logging code, and some services that it runs all the time, and an API" is really ugly. You have to go out of your way today to structure things that way, because everything is fighting you by forcing you to compose different things in different ways, and encouraging you in a million subtle ways to do something that will add a little spiky bit to your code that will make it impossible to compose. Consider just the HTTP handler. How many "routers" out there make it easy to encapsulate a particular sub-application on a particular URL fragment like "/myforum", and then all you have to do to move the application to a different URL is simply route it to something different like "/public/myforum", and no other changes have to be made? The ones I know that allow that don't particularly encourage it, and there's plenty for which it's all but impossible. It doesn't take many things that can't be composed very well to make composition difficult, and very few things in programming make composition easy right now.