What Kind of Language Is Ruby?

In the old days, the distinction between languages was simple: they were either compiled, like C or Fortran, or interpreted, like BASIC. Compiled languages gave you speed and low-level access; interpreted languages were higher-level but slower.

Times change, and things aren't that simple anymore. Some language designers have taken to calling their creations ``scripting languages.'' By this, we guess they mean that their languages are interpreted and can be used to replace batch files and shell scripts, orchestrating the behavior of other programs and the underlying operating system. Perl, TCL, and Python have all been called scripting languages.

What exactly isa scripting language? Frankly we don't know if it's a distinction worth making. In Ruby, you can access all the underlying operating system features. You can do the same stuff in Ruby that you can in Perl or Python, and you can do it more cleanly. But Ruby is fundamentally different. It is a true programming language, too, with strong theoretical roots and an elegant, lightweight syntax. Youcouldhack together a mess of ``scripts'' with Ruby, but you probably won't. Instead, you'll be more inclined toengineera solution, to produce a program that is easy to understand, simple to maintain, and a piece of cake to extend and reuse in the future.

Although we have used Ruby for scripting jobs, most of the time we use it as a general-purpose programming language. We've used it to write GUI applications and middle-tier server processes, and we're using it to format large parts of this book. Others have used it for managing server machines and databases. Ruby is serving Web pages, interfacing to databases and generating dynamic content. People are writing artificial intelligence and machine learning programs in Ruby, and at least one person is using it to investigate natural evolution. Ruby's finding a home as a vehicle for exploratory mathematics. And people all over the world are using it as a way of gluing together all their different applications. It truly is a great language for producing solutions in a wide variety of problem domains.

Is Ruby for Me?

Ruby is not the universal panacea for programmers' problems. There will always be times when you'll need a particular language: the environment may dictate it, you may have special libraries you need, performance concerns, or simply an issue with training. We haven't given up languages such as Java and C++ entirely (although there are times when we wish we could).

However, Ruby is probably more applicable than you might think. It is easy to extend, both from within the language and by linking in third-party libraries. It is portable across a number of platforms. It's relatively lightweight and consumes only modest system resources. And it's easy to learn; we've known people who've put Ruby code into production systems within a day of picking up drafts of this book. We've used Ruby to implement parts of an X11 window manager, a task that's normally considered severe C coding. Ruby excelled, and helped us write code in hours that would otherwise have taken days.

Once you get comfortable with Ruby, we think you'll keep coming back to it as your language of choice.