John MacFarlane, the developper of Pandoc, has released a new Citeproc that generates citations and bibliographies using CSL style files (CSL= citation style language). While it is written in Haskell and while it's primarily intended for use with Pandoc, it can also be used in other contexts. Provided with a JSON encoded list of references via stdin, it can produce formatted output.
The man page of the new citeproc executable, for those who are interested: https://github.com/jgm/citeproc/blob/master/man/citeproc.1.md
I know that ConTeXt has its own infrastructure to format bibliographies and citations, but, given the enormous amount of available styles in CSL, I nevertheless think that this could be a worthwile addition. What would be necessary to make such a toll usable with ConTeXt? How complicated would that be?
In principle, this should be trivial. Define a new command, say \citeproc[ref], which saves the values of `ref` to a lua table, and at the end of the run, write that lua table to an aux .json file, call citeproc and store output to a new file, and on the second run read from that file. This is essentially how the old bibtex used to work. Note that this scheme has a few drawbacks: First, it needs to call an external executable, which can be slower than directly reading the bib file via lua. Second, it creates a bunch of extra auxiliary files, which is always annoying. But I do agree that it will provide us with the ability to use the large number CSL styles. Of course, a better option will be write a CSL processor in Lua, but that is a lot of tedious (but relatively simple) task. I wonder if there is already a CSL processor written in Lua. Aditya