Rendering OCaml document is widely known as a very difficult task: The ever evolving OCaml module system is extremely rich and can include complex set of inter-dependencies that are both difficult to compute and to render in a concise document. Its task is even harder than the typechecker at it also needs to keep tracks of documentation comments precisely and efficiently. As an example, signatures such as include F(X).T and destructive substitutions were never handled properly by any documentation generator.

Odoc is the latest attempt at creating a documentation tool which handles the full complexity of the OCaml language. It has been a long time coming as tackling both the module system and rendering into rich documents makes for a difficult task. Nevertheless we believe the two recent developments provides the final pieces of the OCaml documentation puzzle. This two improvements split odoc in two layers: a model layer, with a deep understanding of the module system, and a document layer allowing for easy definition of new outputs.

This talk will give a tour of the architecture of odoc, including how the model layer performs the jobs of path, fragment and reference resolution, signature expansion, and how aggressive caching can help with the performance. The talk will then present the document layer, its general structure and give an introduction on how to contribute new outputs. The rest of this abstract provides a glimpse of some challenges present is these two layers.