Dear Mr Sloan,
sorry for the late reply. I was on vacation, and so were others from the pdfreaders team.
* Robert Sloan sloan@uic.edu [2011-07-26 11:13:31 -0500]:
Is there a reason why you don't list the Skim Reader as one of the options for Mac OS X? It is certainly open source, so I'm wondering if it fails other requirements you may have, such as license.
Unfortunately Skim is not entirely Free Software. Only the front-end of Skim is available under a Free license, the back-end (its rendering engine), which does most of the work of reading PDF files, is under a separate, proprietary license.
Statements on sourceforge about Skim's licensing only refer to the parts which are Free Software; sourceforge does not host all parts of Skim that are required to make it work, including those parts which are proprietary.
This is why we do not list Skim on pdfreaders.org, although we have been aware of it for some time.
I was also wondering if you happen to know of any good statistics about the uptake of open-source PDF viewers among Windows users. I am doing some scholarly writing about software vulnerabilities, and it led me to wonder whether any of the reasonable alternatives to Adobe Reader for the 90% of the world running Windows are getting any significant use.
No, unfortunately we don't have any statistics.
If there is anything else, please let us know.
Best regards, Matthias