A quick word on why I choose to code in Smalltalk in my spare time, and why I enjoyed the hell out of working with it full-time, several jobs ago.
To put it simply, there is a feeling of delight, wonder and power when coding in a good Smalltalk environment (such as Squeak/Pharo or VisualWorks) that is unmatched by any other environment and IDE.
Like tasting fruit from the Goblin Market in the poem, and then forever pining away for it, working in Smalltalk spoils you for other languages (I’ve worked in C++, Java, Perl, Python, Ruby and Lisp) and development environments (tried VisualStudio, Eclipse, Emacs, vim, TextMate).
The two things that you spend most of your time doing as a programmer — coding and debugging — are made noticeably easier and more fun by that combination of Smalltalk language and IDE. The language syntax is small, powerful, expressive, introspective. The entire stack (and libraries, and IDE) is written in Smalltalk (turtles all the way down), and you have access to the source code, allowing you to study and extend all operations, basic and complex. The code organization — explicit, first-class visual IDE support for packages, classes, protocols (groupings of methods by intended use) and methods — is extremely helpful.
The debugger… is a thing of deep beauty. The ability, while, say, developing a web app, to not only set breakpoints and examine the state of the running program (even, if you set it up right, through the web browser itself — remind me to tell you about “halos”), but to be able to interact with the objects on the execution stack dynamically (i.e. call methods on them, and examine their output), and also to change code and resume execution from mid-halt… is freeing beyond belief.
The above things, by themselves, would merely make me like the language a lot, and miss its convenience. But the thing that makes it truly indispensable for me is Seaside, a web framework.
It is unorthodox, flexible, powerful, and… difficult to describe. I’m going to let people much more eloquent than me attempt to do so:
* Secrets of lightweight dev success, Part 8: Seaside
* A SeaSide Vacation
What’s the downside of working with Smalltalk, though? (Just ask the Lispers what the downside of working with Lisp is), rather than, say, in other sufficiently elegant and pleasant languages such as Ruby or Python?
In short, less popularity and a smaller developer base. Which means less third-party libraries, tools and open source projects. So, you’re a bit out there on the bleeding edge (which is funny, because Smalltalk is 30+ years old, but again, ask the Lispers about that).
The upshot, then is this. If you’re working on a well understood and often-solved problem (for example, CRUD-type record maintenance over the web), use something like Rails, Django or web2py. But, as is just as often the case, if your project is way off the beaten path (like, say, a web mud), Smalltalk and Seaside just might be perfect for you. And in any case, it is worth trying out for a week or a year. You will learn a hell of a lot.