As such, it could open a PDF file as long as the %PDF-header started within the first 1024 bytes of the file. There’s, however, a change in the scheme of things now.

I am not sure why but people treat PDF differently than image files so I don't think there are very many that work for quickly viewing PDF *and* image files but you can certainly use something ...

A PDF — which stands for Portable Document Format — is an open standard document file extension created by Adobe. It has gained popularity in recent years because of the ease of use it affords ...