Hi Peter,
Ok, but right now there is no version of MuPDF for Mac OS, so why providing a link to it? Vindaloo's binaries are 5 years old, the library it use to render the PDF has been patched many times in 5 years[1], running this binaries is not secure. Also, it's compiled only for the ppc platform, people running the latest version of OS X, won't be able to run it, people running slightly older version of OS X on an intel machine will have it running inside and emulator, the application will be slow to start, and i'm afraid it might give a bad impression about free software. Xpdf require X!
Indeed, the situation on OSX is not ideal. We will discuss the recommendations for OSX further in the team.
Why not linking to Skim[2], which is a **native** PDF viewer for OSX, under a BSD license, and having some advantages over the default app?
Skim uses the proprietary PDFKit-backend for rendering PDF. Since the rendering component is the core of a PDF-Reader, we can't recommend Skim. Similarly we don't recommend Firefox with a proprietary plugin, as a free PDF-Reader.
I hope you understand that. Maybe you can convince the Skim developers to switch to a free backend. IIRC there is popplerKit aswell, although I am not sure on the current status.
Best Regards, Hannes