Japanese warning signs are very different than warning signs in other parts of the world, because they usually contain a visual and easy to understand reason why something is dangerous or not allowed.
Guy Steele's keynote at the 1998 ACM OOPSLA conference on "Growing a Language" (mostly about JAVA) discusses the importance of and issues associated with designing a programming language that can be grown by its users.
"Creation is a process, and strangely, by looking at how everyone’s favorite plushy first-mate sprang into existence, we can learn a lot about any collaborative creative endeavor."