mossmoth

You have Sailfish OS [0], which is ported to rather modern (albeit somewhat low spec) phones (e.g. Fairphone 2, Jolla C [1]). Sailfish also has an Android compatability layer (think Wine for Linux) so it can run most Android apps.

[0] - https://sailfishos.org/ [1] - https://en.m.wikipedia.org/wiki/Sailfish_OS#Hardware_overvie...

Datalog is also quite actively used in ontology based data access where Datalog rules are used as mappings between databases and ontologies (see e.g. [1]). Variants and extensions of Datalog is also research actively in the field of answer set programming[2], with many usable implementations.

[1] - http://ontop.inf.unibz.it/ [2] - https://en.m.wikipedia.org/wiki/Answer_set_programming

I do not think you are correct in saying that SQL is a logic programming language. A logic programming language is defined in terms of rules/implications[1], which SQL is not. However, it is a declarative language, which Prolog also is. In a declarative language you state what a solution is[2] (which the program then searches for), in contrast to the more traditional type of programming (imperative) that states how to obtain a solution.

[1] - https://en.m.wikipedia.org/wiki/Logic_programming [2] - https://en.m.wikipedia.org/wiki/Declarative_programming