Ciao is a Prolog-based logic programming system. As introductory material we recommend the following:

Reference Manuals

Manuals of the main bundles of Ciao:

  • ciao: compiler, toplevel, core libraries
  • ciao_builder: build system
  • lpdoc: documentation generator
  • ciaopp: analysis, verification, (static) debugging, and optimization
  • ciaodbg: testing, profiling, and (dynamic) debugging
You can browse the available bundles and their manuals in the bundle catalog.

Tutorials and Presentations

  • An overview paper on Ciao (PDF)
  • Some tutorial slides on Ciao features, relatively old (PDF, HTML).

    • Some tutorial slides on LPdoc (PDF, HTML).
    • Some recent introductory slides on Ciao and CiaoPP (PDF)
    • A brief tutorial on CiaoPP (PDF).


The Ciao System incorporates many years of results in programming languages research. See our list of publications available on-line and their references.