[superphunthyme]

It appears to be a "MacWrite II document" according to http://mark0.net/onlinetrid.aspx

[woodruffw]

Thanks for the link! I had tried running `file` on it, with no success ;)

[cheiVia0]

It is definitely not MacWrite since it doesn't conform to the format:

http://fileformats.archiveteam.org/wiki/MacWrite

Looks like it is actually Word for Mac:

https://www.w3.org/History/1989/proposal.html