SWI-Prolog 8.0.3 Reference Manual: Section 2.5

## 2.5 GNU Emacs Interface

Unfortunately the default Prolog mode of GNU Emacs is not very good. There are several alternatives though:

- https://bruda.ca/emacs/prolog_mode_for_emacs
  Prolog mode for Emacs and XEmacs maintained by Stefan Bruda.
- https://www.metalevel.at/pceprolog/
  Recommended configuration options for editing Prolog code with Emacs.
- https://www.metalevel.at/ediprolog/
  Interact with SWI-Prolog directly in Emacs buffers.
- https://www.metalevel.at/etrace/
  Trace Prolog code with Emacs.