IMSLP Forums

Is there some kind of machine-readable interface or API to the IMSLP database? That is, some way that a native client could access data from IMSLP in XML or other machine-parseable format, thus saving load on Mediawiki and headaches on the programmer?

Not a pressing issue, by any means.

If you mean data like the meta-data for the music scores (editor, publisher info, etc.), then no. This data is not stored separately in a database, but only inside the wiki code of the individual pages, so one would have to extract it from the individual pages in order to access it.