The ONP ‒ full name Ordbog over det norrøne prosasprog, engl. a Dictionary of Old Norse Prose ‒ is a large scale dictionary project based in Copenhagen. The project’s goal is to produce a comprehensive dictionary of the prose language of Old Norse, a goal on which they have been working since the project was started in 1939. So far 3 volumes (a-em) plus a volume of indices have appeared in print. In recent years, however, it seemed that the project was going through some difficult times as it became clear that the printing of new volumes was not going to continue. That is sad news to anyone interested in the Old Norse language, since the ONP was set out to be a tremendous achievement, vastly superiour to any other dictionary of Old Norse currently in existence. Not all is lost, though, with the project apparently shifting its focus on digitizing the material which was so far collected. In fact, it appears that a lot of data has already been made available online.
Certainly, this isn’t as good as having the dictionary completed in print, but what they offer online is already a very useful ressource and a big leap forward from the heavily outdated dictionaries of Cleasby/Vigfusson and Fritzner.
I can’t tell you in detail how complete the available data is, but judging from some random samples I looked up, it appears to cover the entire alphabet, and the entries certainly seemed useable, even though they are obviously in an “un-edited” state.
Information on their web page indicates further that they do have plans to continue employing editors, although I’m now quite sure what and how they will edit / publish.
All in all, this makes me particularly happy for two reasons: First, because it will make my life as a researcher easier (the ONP lists full word forms, making it possible to judge the inflectional behaviour of words), and second, because it was about time that the work of the tireless staff at ONP was finally made available to a wider audience.