In addition to my list of eight, in another comment here, I am throwing in Logtalk. I wouldn't label it as "9", given that it came out in 1998, but it's worth n

In addition to my list of eight, in another comment here, I am throwing in Logtalk. I wouldn't label it as "9", given that it came out in 1998, but it's worth noting, because it is still developed, and because its depth fits with the spirit of the original post. "Logtalk is an object-oriented logic programming language that can use most Prolog implementations as a back-end compiler. As a multi-paradigm language, it includes support for both prototypes and classes, protocols (interfaces), component-based programming through category-based composition, event-driven programming, and high-level multi-threading programming." - http://logtalk.org http://logtalk.org "Logtalk is an object-oriented logic programming language that extends the Prolog language with a feature set suitable for programming in the large. It provides support for encapsulation and data hiding, separation of concerns and enhanced code reuse. Logtalk uses standard Prolog syntax with the addition of a few operators and directives. Logtalk is distributed under an open source license and can run using ISO-compliant Prolog implementations as the back-end compiler." - http://en.wikipedia.org/wiki/Logtalk http://en.wikipedia.org/wiki/Logtalk