[Zak]

I would add a third category, which is not exclusive with the other two: languages that provide good tools for abstraction.

The pitfall with #1 is leaky and obscure abstractions. It's easy to write code that has performance problems or requires a lot of understanding of moving parts not actually related to the problem at hand. Where's the code responsible for putting the current state on a web page? All I see is a bunch of monad transformations and I don't know what they're for! Sure, I can figure out what's going on eventually, but I'll have to read a lot of CS papers first.

The pitfall with #2 is lack of ability to write a suitable abstraction for the problem. Instead, the problem has to be fit to the language. You end up with either something relatively simple, but inflexible or a large amount of incidental complexity. Why do I need to implement AbstractThingPutterOnPageGenerator and generate a ThingPutterOnPage before I can put a thing on the page? Couldn't this just be called putThingOnPage() and use some optional args when the default behavior doesn't cut it? Sure, I can figure out what's going on eventually, but I'll have to read a lot of code first.

I think Lisp has always been strong in the third category, and that Clojure is a Lisp especially suited to real-world use right now. The heavy emphasis on defining code in terms of generic operations on generic data structures is a particular strength. For something more mainstream, Python does pretty well here. That's largely cultural though; Python has a very comparable feature set to Ruby, but Ruby's community doesn't have "explicit is better than implicit", the lack of which can lead to code which is impenetrable rather than merely dense.

[tormeh]

The problem with Lisps is that generally speaking, they're all interpeted, which means type errors are discovered at runtime. Which sucks for maintenance.

[Zak]

Most implementations of Common Lisp have ahead of time compilation, at least as an option, but also have the compiler, or sometimes a different compiler or an interpreter available at runtime. Clojure is also typically AOT-compiled to JVM bytecode.

Did you mean that Lisps are dynamically-typed? That's true, and whether it's mostly good or mostly bad is a religious topic that almost certainly lacks one true answer. My own take on it is that I program very interactively and static typing feels like an impediment to that most of the time. Furthermore, type errors are usually a small subset of the possible errors and many static type systems allow any type to be null anyway, drastically reducing the benefit.

[yarrel]

Common Lisp is compiled and has a type system.

Several type systems.