Open Source PDF reader for windows as an alternative to Adobe reader

Evince is working on Windows now, but there's no binaries yet, so you'll have to build it yourself.

I use Sumatra PDF viewer. It seems to work rather well, it loads almost instantly (compared to 20 or so seconds for adobe) and is very fast with page changes and what not. Also, no ads unlike Foxit.

I recently deployed Foxit to replace Adobe Reader at our company. I pushed out a custom INI that turned off JavaScript and the ads (I was surprised to find that the ads were a simple configuration option, and even more surprised to find that all this was in a @&*($&^! INI in the Program Files\Foxit directory), as well as a few other custom options.

I, too, was hoping for an open source solution, but Foxit was the only thing that met our needs, and with the INI preference changes and a permissions change to let normal users read and write to the preferences INI it seems to work like a charm.

MuPDF. Brought to you by artofcode LLC & Artifex Inc. -- the same people that develop Ghostscript.

• Open Source as preferred by Tom Feiner,
• multiplatform (Windows, Mac OS X, Unix, ...soon maybe Android, iPhone too?),
• very lightweight (see screenshots below) --
  the highly-rated SumatraPDF from this answer uses MuPDF as its rendering foundation,
• full Unicode support,
• very fast,
• secure as defined above (no JavaScript support),
• very surely not bloated with features,
• not displaying adds (unless you deem the copyright notice in the "About" screen as one...),
• nicely looking and easy to use....
  hmmm, decide yourself: the interface is very simple (keyboard navigation only, no menues or icons):

It might sound odd, but how about an old version of Adobe Reader, back when it was called Acrobat Reader? v6 can open pretty much all PDFs (except the ones with the fanciest features), it's small, and fast...