---+ Is there a Java interface to Prolog?

JPL is integrated into the full SWI-Prolog distribution starting with
version 5.4.x, including binaries for MS-Windows and a Linux RPM.
Documentation is -like all integrated packages-, available from the
[[SWI-Prolog website][<pkg:JPL>]] and from the
local manual browser under Help/Package documentation. Examples are
included in the directory =|doc/packages/examples/jpl|= relative to the
installation directory. These examples include embedding Prolog in Java
as well as the other way around.

JPL is actively maintained by Paul Singleton.