Richard Kennaway's Constructed Languages List: "Constructed languages are languages which are intended to be spoken by people, to people (as distinct from, say, programming languages), and which have been deliberately constructed rather than having evolved. There is a vast number of these, most of which are never used by anyone but their inventor. Only a handful have ever had a significant circulation, but with the advent of the World Wide Web, it now becomes possible to make one's ideas available to all at little cost."

My: there's some funny people about.