If you need a lightweight PDF Reader, you may want to try Foxit Reader. Faster than many big competitors like Adobe Reader, it consumes little RAM and hard drive space.
We often talk about software to create, merge or edit PDFs. What can you do when it comes to protecting PDFs from text edits and copies? There is specific software for that. PDF Anti-Copy is an interesting one: it's an incredibly simple solution, but one that does what it promises.
Adobe Acrobat Reader DC is one of the most powerful PDF software in the world, and although a lot has changed in the last few years, Acrobat still is the software of choice for your pdf reading needs. It’s a free download from Adobe’ site.
Sumatra PDF is a versatile free software that can quickly open many different file formats. It’s a stripped-down version of a reader, but it pays off because the software is sleek, quick and almost crash-proof.