.p65 is PageMaker 6.5, which is the same file format is PageMaker 7 (whose files are labeled .pmd). And, yes, .ai is some sort of Illustrator file, though it could be any version. PM 6.5 and 7 files can be opened in InDesign if you don't have PageMaker. Illustrator 10 is the best choice for older version files. If someone was still using PM 6.5, though, the likely version of Illustrator they'd be using would be 6 or 8--they're contemporary to that version of PageMaker. On Dec 5, 2003, at 12:26 AM, VS wrote: > At 22.58 -0800 03-12-04, Robert (Bob) P. Andris wrote: >> Does anyone know of a list of app extensions? I was given some files >> that end in ".p65" and some that end in ".ai". Trying to find >> something that will open them. > > .ai is Adobe Illustrator, that is my strongest guess. > There are some places on the webb where you can look up extensions, > here is one such place. > http://whatis.techtarget.com/fileFormatA/0,289933,sid9,00.html > > As this is a returning problem for me as well I am grateful for tips > on other such sites.