(Originally posted 2003.Jun.08 Sun; links may have expired.)
When I was in high school, in the 1980's, I discovered a book on Esperanto at a library and studied it. I bought a few books, and even acquired (I don't recall how) a record album of folk songs recorded in Esperanto. It was interesting, but I never had anyone to speak it with. For academic credits in high school and college, I took Latin, another language I didn't use for speaking purposes. In case you haven't heard of it, Esperanto was one of the first "artificial languages," a language created to be culture-neutral, to enable international communication. It has very simple rules of grammar, and a vocabulary adopted from root words of many European languages. Esperanto is reported to be ten times easier to learn than a typical European language.
Created over a hundred years ago, Esperanto was not just a language, but a movement for international understanding and peace. It was denounced by Hitler and banned in Nazi Germany. The USSR in 1938 shot or deported Esperanto speakers. Pre-WWII Japan mistreated and sometimes executed Esperantists. In the USA during the McCarthy era, Esperanto was associated with Communism (and perhaps some American Communists were using it as a 'secret language'.)
Perhaps at its height of popularity, between one and ten million people spoke Esperanto world-wide. In recent years, it has been reported that Klingon and Elvish are two artificial languages with more speakers than Esperanto, though I think more people are actually fluent in Esperanto than Klingon.
Why am I talking about Esperanto? Partly because I just read an article about it in the San Francisco Chronicle, which reports that about 25 people in the Bay Area get together to speak it monthly. It quotes ELNA vice president of public relations Charlie Galvin as saying "For me, I like Esperanto because it's like a secret club. I like the fact that few people know it. It makes it special." That is so depressing, in light of the intent of Esperanto's creator.
Esperanto will always be a little-known language because there is no economic reason to learn it - and that's just fine with the Esperantists. The Esperanto-enabled travel service is free and non-commercial. In this day of international organizations (both commercial and non-commercial), Esperantists are no longer making the case that that a simple-syntax, easy-to-learn language could help people communicate with each other on a level playing field, with value gained in commercial as well as non-commercial arenas.
Another reason I'm talking about Esperanto is that it reminds me of Smalltalk. Like Esperanto, Smalltalk has a simple syntax that is pretty easy to learn. Esperanto was invented by an idealist wanting international communication. Smalltalk was invented by idealists who thought it could be a computer language easy enough for children. Like Esperanto, few people today have an economic reason to use Smalltalk. No big companies are hyping Smalltalk the way Sun hypes Java, or Microsoft hypes C#. Even IBM, which sells a Smalltalk environment, is putting more energy into Java than Smalltalk.
The rules of grammar for Esperanto can be written down in few pages, including all the exceptions. The rules of Smalltalk's grammar are also simple. This PDF explains Smalltalk syntax in relatively few pages: http://www.speakeasy.org/~podenski/stug/reading-smalltalk.pdf.
Smalltalk syntax is unusual today, though I find it easier to read than Perl or Ruby. Objective-C is a language that adds object-oriented constructs to the C language using a syntax similar to Smalltalk. One of my coworkers complained "why isn't Objective C using Java or C++ syntax?" Because it predates C++. When Objective C was invented, Smalltalk was the leading OO language. Now Smalltalk is one of the language reported as dead or near-dead by Wired magazine.
Objective-C is regaining mind-share these days because it is the recommended language for implementing GUI applications on MacOS X using the Cocoa class library. There is an economic reason for people to adopt that language -- it is the easiest way to put a really nice GUI on non-gui unix-compatible code on MacOS X. At least five books on Cocoa programming have been published in the last year on Cocoa, and every one teaches the OO parts of Objective C in the opening chapters.
Unlike some Smalltalk implementations, Objective C on MacOS X plays well with others. Linking C libraries and Objective code together is trivial. Even though the Cocoa class library is implemented in Objective C, you can write Cocoa-using applications in Java, Python, AppleScript, Ruby, and a Smalltalk-like scripting language called FScript. (C++ is too "static" to easily interoperate with classes written in dynamic languages, but Apple's version of 'gcc' allows mixing C++ and Objective C code if one is careful to cope with the differences in object allocation and deallocation.)
I would use Smalltalk it if had native GUIs on MacOS X and Windows. If it interoperated with Cocoa on MacOS X. If it easily interoperated with C libraries. If it could be used to implement shared libraries (TWAIN plugins) and other non-application code on the two platforms I need to support, and not have to be written in "dialect dependent" forms on each platform. If it didn't freak out my coworkers. If it wasn't a "secret language."