DiffPDF is a great, free (gpl) Windows program, belonging to the category Productivity software and has been created by Qtrac.
More about DiffPDF
DiffPDF is a light program that needs less free space than the average program in the section Productivity software. It's very heavily used in countries such as Australia, India, and Spain.Since we added this program to our catalog in 2012, it has managed to obtain 7,160 downloads, and last week it had 5 downloads.Its current version is 1.1.5 and was updated on 6/20/2012. DiffPDF is available for users with the operating system Windows XP and previous versions, and you can download it in English.