We're all familiar with Adobe Reader - most of us probably use it daily to view PDF files - but it's very ubiquity has made it a prime target for hackers, and it's frequently in the tech news as a result, and it's often suggested that users consider using alternatives.
So, what alternatives have we? There are many options, but pundits suggest...
Foxit Reader - free, reputed to be small and fast, supports adding annotations and text to existing PDF files. PCworld reports installation also installs a browser toolbar and changes the default search engine to Ask unless the user disables these options. Available for Windows 2000/XP/Vista/7/8 & Linux. More information here - http://www.foxitsoftware.com/Secure_PDF_Reader/
Mobile versions for iOS and Android are also available.
Need to generate PDF's? You could consider purchasing Foxit PhantomPDF http://www.foxitsoftware.com/products/phantomPDF/ or Foxit Advanced PDF Editor - details here http://www.foxitsoftware.com/products/editor/ (Windows only)
Sumatra PDF Reader - claimed to be speedy, and light on system resources, free, PDF file viewer for Windows XP/Vista/7; also able to display several ebook formats such as Mobi, epub and others. Open source. More info at http://blog.kowalczyk.info/software/sumatrapdf/free-pdf-reader.html
Nitro PDF Reader - free, reputed to be small and fast and offers print to PDF ability, allows documents to be annotated and text to be extracted from and added to a PDF document, supports Windows XP/Vista/7 and has 64 bit as well as 32 bit versions. www.nitroreader.com for more information. Looking for even more features, or a full fledged substitute for Acrobat Reader - you may want to consider purchasing Nitro Pro - www.nitropdf.com for more information.
Those may suit the Windows world, but what of systems other than Windows...?
For Linux a few alternatives come to mind - Okular, Evince, and even Foxit. Each have their adherents, but we were curious to know which of the current Windows based favourites could be used on Linux with a "compatibility layer", or "emulator".
We tested the "portable" Sumatra PDF Reader using WINE (Wine Is Not an Emulator) on openSUSE Linux 12.2; it ran successfully, and as expected, it did not allow typing into PDF forms, but it was extremely fast, and installation was trivial!
Nitro PDF Reader installer failed to run with WINE, but the Foxit download installed happily, and seems to run great! We did not exhaustively test all of it's features, but we were impressed with the way it was able to handle PDF documents containing forms. Foxit has a native Linux version available for download, but it is considerably older and less polished than it's Windows counterpart.
Mac users have Preview, Skim, Free, Read Right, PDF Sam and other interesting possibilities. We've not had time to test any of these, but it's nice to have so many decent alternatives to choose from, and indeed your editor has now gone 10 weeks without Adobe Reader installed, using a combination of Okular and Foxit Reader (for Windows) to handle PDF's.
The security issues with Adobe Reader, and the one with Foxit Reader discovered and remedied a few months ago, should however remind us to always stay alert for security patches and keep our software up to date, whatever we choose to use!