Hi, have been wondering this for a while now. Shrugged it off as not important until I've realized the number of books piling up in this format. What is ARK (Arkenstone)? What program does one need to open these files? Are they Open Book-related, or something different. I'm only familiar with Kurzweil and the various Windows-related formats. However this may be something that I just missed along the way in learning about. I wouldn't have wondered about it so much except that there are quite a few books up on the validation page in arc format that have been there for quite some time. I'd happily download and validate some of these if I knew what the file types were. If I have the program to open them, I can do that, but I think it is some sort of scanning software. I vaguely remember there was a scanning program associated with these, but I don't recall which. Are they easily converted, or must you have that specific software. A lot of those books would be interesting to read though, and it'd be good to get them off the download page and onto the site. Any thoughts? Best, Allison H.