[Inkscape-user] need help installing software for reading .ps files

I need to open a .ps file. I've installed pstoedit onto my computer. I see from the readme file that I also need to install ghostscript, but each time I try to do this a pop-up window appears telling me I need to install it using win-zip and that this will cost me money. I'm confused. Is ghostscript not open source as well, or am I just clicking on the wrong download?

Thanks.