The best kind of progress

(written by Lawrence Krubner, however indented passages are often quotes)

The progress made by Common Lisp:

I once saw an interview on television with a font designer from Bitstream Inc. about how he conceptualized the process of font design. It is not about designing the shape of the letters, he explained, much to my initial surprise. Then he went on to explain that it was really about the shape of words. The font shapes play into that, but they are not, in themselves, the end goal. Programming language design is like that, too. It’s not about the semantics of individual operators, but about how those operators fit together to form sentences in programs.

Unlike the situation with fonts, where whole books can be viewed instantly in a new font to see how the design works, we don’t know in advance what sentences will be made in a programming language. We have to wait and see what people choose to write. Common Lisp took a step forward, and while we can quibble endlessly over whether any given design decision was right, the one design decision I’m most certain was right was to offer the community a rich set of capabilities that would empower them not only to write programs, but also to have a stake in future designs. Never again will I fear sending out e-mail to a design group asking for advice about what the semantics of HANDLER-BIND should be and finding that no one has an opinion! To me, that kind of progress, the evolution of a whole community’s understanding, is the best kind of progress of all.