A old text file with special format

Question

I am working on HP-UX project, there are a old document. Can open it with vim, but there are some special character among text. For example:

.P
   "xxxxx"
.AL 1 10
.LI  "xxx"
.H 3 "xxxx"

It looks like html but not be html. Is it possible convert it to modern document?

Answer 1

Looks like troff. Install GNU troff (Groff) and try:

groff -Thtml -pet -mm input.mm > output.html