However, if literate programming stands as a comprehensive programming methodology at one of end of the spectrum and no documentation stands as its antithesis, then Marginalia falls somewhere between. That is, you should always aim for comprehensive documentation, but the shortest path to a useful subset is the commented source code itself.

" ... Kelp is a framework for taking notes about source code files in a simple way. It is composed of a set of command line tools, and a text file format. The text files contain annotations and can be written using any standard text based editor. The tools retrieve the annotations using a sophisticated search pattern.

Since annotations are stored separately from the source code module they describe, Kelp is a natural fit for annotating third-party libraries. When it is not possible, or desirable, to insert clarifying comments into code that could be replaced/erased by the next release, Kelp succeeds at keeping your annotations current and pertinent. ... " Possible wikispammer, but interesting enough to check out