Bruce said:
any reader is better than Adobe.
I take such statements with a large grain of salt. They reek of bias
with no evidence. When I selected PDF-XChange in my prior trials of PDF
viewers, it was because it had better security than Adobe's Reader. I
could disable Javascript in PDFs (something that I've only encountered
in intra-company generated PDFs). I could disable running a "launch"
command stored in the PDF file when it was loaded in the viewer (which
wasn't only to launch an .exe but could be a filetype that some other
handler had to load). I could restrict attachments to PDFs (yep, they
can have attachments) to allow only .pdf files and no other filetype.
Didn't have those security options in Adobe Reader until, I think,
version X (10). Adobe Reader now has similar security options plus it
has its sandbox in which to load PDFs. Yes, Adobe Reader is obviously
more targeted by hackers looking for vulnerabilities but that itself
doesn't render other PDF viewers as more secure, just less targeted.
Overall, it appears Adobe Reader's security is better than the other
free alternatives.
I haven't bothered yet to look at the disk and memory footprints for
Adobe Reader versus PDF-Xchange. I do recall when there was a
discussion about Nitro PDF that I looked at it and, geezus, was it a
pig, and slow, and lacking.
An item that bothers some folks is whether a PDF viewer requires the use
of Ghostscript (to support the Postcript conversion). Well, either you
can include a library from which you can call functions or issue a
command via CLI or you roll it into the .exe to bloat it. The only
issue I have with Ghostscript is whether a PDF viewer app wants to
install a global instance of it (that all programs access when they want
to issue Ghostscript commands) or if it installs a private instance in a
subfolder in the folder where the PDF viewer got installed (so only that
app uses that instance of Ghostscript). The latter addresses separation
of different versions of Ghostscript upon which a viewer app relies.
Later versions may drop some functions, change syntax, add or remove
arguments, or otherwise change behavior in Ghostscript from what the app
expects. This is like the old DLL Hell problem where programs were
dumping their DLLs into the same Windows subfolder. The cure was to
separate the DLLs and works, too, for keeping separate different
versions of similar supporting software.
PDF-Xchange includes a private install of Ghostscript. As I recall,
PDFCreator did a global install of Ghostscript (so it could affect every
other program that used that Ghostscript). I don't have Foxit Reader
installed but someone that does (you) could check if there was a global
or private install of Ghostscript for it or if it use a proprietary
library of Postscript functions.