On OS X, is there a good application to open PS files without converting them to PDF?
In addition, I want to associate PS.GZ files to this application, but retain the TAR.GZ association to my uncompressor. Is this feasible?
There are several possibilities:
Preview.app (comes with OS X) will open any PS (PostScript) file. In the background, I assume, a conversion to PDF takes place, but this should not be an issue.
Adobe Illustrator can open and edit PostScript files. Shelling out a rather big amount of money for just viewing a PS file seems overkill, though. However, there is a free 30-day-trial (link from January 2013 for CS6).
PostView by Metaobject is said to support PostScript as well, but I personally am not convinced / could not get it to work.
My personal recommendation: Use Preview.app!
To answer your first question:
No need to download anything to open the *.ps file without converting just open your terminal.
open -a textedit filename.ps
It will open a *.ps file like Ultraedit.