SWI-Prolog offers a variety of development environments, most of which may be combined at will. The native system provides an editor written in Prolog that is a close clone of Emacs.
It provides semantic highlighting based on real time analysis of the code by the Prolog system itself. Complementary tools include a graphical debugger, profiler and cross-referencer. Alternatvely, there is a mode for GNU-Emacs and an Eclipse plugin, both of which may be combined with the native graphical tools.