Like JavaDoc, the PlDoc infrastructure is based on structured 
comments. Using comments, no changes have to be made to Prolog to 
load the documented source. If the library(pldoc) library 
is loaded, Prolog will not only load the source, but also parse all 
structured comments. It processes the mode-declarations inside the 
comments and stores these as annotations in the Prolog database to 
support the test framework and other runtime and compiletime analysis 
tools that may be developed in the future.
Documentation for all or some of the loaded files can be written to file in either HTML+CSS or LaTeX (see section 10.5) format. Each source file is documented in a single file. In addition, the documentation generator will generate an index file that can be used as an index for a browser or input file for LaTeX for producing nicely typeset document.
To support the developer, the documentation system can be asked to start a web-server that can be used to browse the documentation.