This may be common knowledge by now, as the database seems to have been launched over a year ago. I had heard about the project earlier but the last time I checked for it, it was still in the process. Now it is freely available here:
together with the twin database of Voigts-Kurtz on the scientific manuscripts in Old and Middle English.
The search-engine is a bit awkward -- it took me some time to find out that in order to retrive full records (not the default abbreviated ones) one must put a double bar || and a space at the end of the search string.