[cctalk] What constitutes a dead computer language

I'm sure there are more "dead" computer languages than there are living ones. However,  what is the definition of a dead computer language.  Here are a few potential definitions (choose one or more or add your own): * If the language is not running, as an interpreter or compiler, on any currently manufactured computer.  Running on antique computers or simulators doesn't count. * If no one is being paid to program in that language or maintain code in that language. * If the standards for the language have not been updated in more than 10 (25, 50)  years. * If the language is no longer being used in a production/commercial environment. * If the language is only being used in the hobbyist/historian/antique/simulation environments. Here is an example question:  There is an in production add on to an antique computer written and being supported in Forth.  The Forth interpreter/compiler is running on a modern ARM based micro.  Even though the target of the product is an antique computer since it is using a current technology micro with a supported forth, I would say that Forth is not a dead language. Here is a list of languages from my past, how many of them are officially dead by one or more of the above definitions? APL Forth Lisp Algol Dibol Focal Occam Prolog Watfor & Watfive Ratfor Flap Ralf Teco (editor and macro language) Pilot DB2 Foxbase Any of the Hp Calculator languages (RPL, HP-41 User code) I'm sure their are dead dialects of BASIC but BASIC is currently supported as Visual Basic and Dartmouth Basic. Please update this list as to whether any of these languages are dead (by the current definition above) or alive.  Also, please add new definitions and languages that are dead or nearly dead. Note:  Dead dialects of a living language don't count.