Actually, a fair number of large companies do use Lisp for some serious work (you’ll find a long list of industrial Lisp projects at http://snipurl.com/e3lv9/). Other programming languages are constantly “borrowing” features of Lisp and presenting them as the latest and greatest ideas. Also, the Semantic Web, which many believe will play a big role in the future of the Web, uses many tools written in Lisp.
Note
The idea behind the Semantic Web is to create a set of protocols for websites to follow so that a computer can determine the “meaning” of information on a web page. This is done by annotating web pages with special metadata (usually in a format called Resource Description Framework, or RDF) that links to common vocabularies, which different websites may share. Many of the tools used for working with description logics and RDF data are written in Lisp (for example, RacerPro and AllegroGraph).
So, Lisp certainly has a promising future. But some may think that learning Lisp is not worth the effort.
How did Lisp get this undeserved reputation?
I think that people use a rule of thumb when deciding what things in life are worth learning. Most people seek knowledge in one of the following three categories:
What many other people learn (calculus, C++, and so on)
What is easy to learn (hula-hooping, Ruby, and so on)
What has value that is easy to appreciate (thermonuclear physics, for example, or that ridiculously loud whistle where you stick your fingers in your mouth)
Lisp doesn’t fall into any of these categories. It’s not as popular as calculus, particularly easy to learn, or as obviously valuable as that loud whistle. If we were to follow these (usually very sensible) rules of thumb, we would conclude that a reasonable person should stay away from Lisp. However, in the case of Lisp, we’re going to throw out these rules. As you’ll see from reading this book, Lisp gives you insights into computer programming that are so profound that every serious programmer should have some experience with this unusual language, even if it requires a little effort.
If you’re still not convinced, you might want to take a peek at the comic book epilogue way at the end of the book. You might not be able to understand everything in there right now, but it will give you a feel for the advanced features available within Lisp and what makes Lisp programming different from other types of programming.