Sumatra PDF 1.5 released on Apr 23, 2011, and includes more important features,

• add support for viewing XPS documents
• add support for viewing CBZ and CBR comic books
• add File/Save Shortcut menu item to create shortcuts to a specific place in a document
• add context menu for copying text, link addresses and comments. In browser plugin it also adds saving and printing commands
• add folder browsing (Ctrl+Shift+Right opens next PDF document in the current folder, Ctrl+Shift+Left opens previous document)

btw,
Last week, I noticed MuPDF trunk adds XPS support, but still has some bugs in windows registers.

Today, I heard from Mark Summerfield

Hi Steven,

I’ve just released DiffPDF 1.2.0.

There are small improvements in the user interface plus a tiny bug fix
of one setting that wasn’t saved/restored correctly.

I am hoping that this will be the last release for quite a while!

I’d be very grateful if you’d create a statically built Windows version:
your build for 1.1.5 is proving very popular!

Thanks:-)

So I compiled and released it in the first time, feel free to download it here

P.S. Change logs

It is a real case, and the author of Turn on Measure Tool in Reader for 25,000 PDF documents has been my customer, he bought my software Batch ReaderEnable, because he has already bought the license of Adobe Acrobat, so he just payed extra USD$39, and he can easily converted 25,000 PDF documents.
And, I’d like to correct something in his requirement,

I work for a city government and I have 25,000 scanned maps as PDF documents. Our users (they have Acrobat Reader(should be Adobe Reader) would like to be able to use the measure tool to measure distances on the maps.
From my research, it seems I need to turn on “Enable Usage Rights in Adobe Reader”(should be “Enable For Commenting and Analysis In Adobe Reader” aka “Reader Enable” and in Adobe Acrobat X Pro, it is called “Enable Commenting & Measuring…” ) in order for that tool to work in Adobe reader. Also from my research, it seems there is no way to automate, or batch process, these action for the 25,000 PDF files. There are some references on the web that LiveCycle can do this(Yes, Adobe LiveCycle can do it, but it is very expensive), but nothing confirmed, and when I called Adobe support they said in face, it was NOT possible to batch “enable usage rights“(“Enable Commenting & Measuring”). At. All. Period.
…

btw, Batch ReaderEnable Updates to Support Adobe Acrobat X Pro