I added the Cornish placenames from the MAGA Kernow masterlist to the places shapefile from OpenStreetMap. After creating a few maps I wished to have some other geographic features labelled. I have done some work on this now. The spellings of placenames below should be considered tentative, and may or may not have been checked by anyone. They should be in the Standard Written Form (Main) of Cornish, if they are not that is an error.

Here are links to some CSV files and shapefiles detailing current progress towards Cornish placenames for various categories of OpenStreetMap features:

In future, these names could be included within OpenStreetMap itself, as a name:kw tag and a renderer written to display them interactively on the web. For a demonstration see Jochen Topf's OpenStreetMap Multilingual Map Test site.