MuPDF is a bundle of PDF tools which includes a simple viewer and an extremely impressive console-based PDF toolkit.
The viewer is lightweight and extremely basic. Launch it, choose your document and it appears in an entirely UI-free window. Browse through it as usual and close the window when you're done.
The program supports a lot of keyboard shortcuts beyond the usual arrow keys, PgUp and PgDn. You can zoom in and out, rotate pages, step 10 pages forward or back at once, go to specific page numbers or bookmarks, run simple searches and more. There's no GUI for this, not even a right-click menu, but if you prefer to use hotkeys it might appeal.
MuPDF also comes with mutool.exe, a command-line utility which options to convert PDF files, clean them up, merge selected pages from multiple documents into one, extract PDF resources, take a low-level look at a PDF's innards (great for checking possibly-malicious documents) and more.
This is all console-based, and takes some experimentation to learn and use. Entering mutool displays your main options, for instance; entering mutool merge gives you more details on the merge command, and so on.
Here's a very simple example.
mutool extract test.pdf 3-5
This extracts all PDF resources - images, fonts etc - from pages 3-5 of the file test.pdf, and saves them to the current folder.
To get just a little more complex, try this.
mutool draw -o p%d.png -r 300 test.pdf
This command takes test.pdf as its input, converts each page to PNG with a resolution of 300dpi, saving the image with the file naming scheme we've described (p1.png, p2.png).
You can probably already guess how to tweak this. Replace 300 with 150 (or whatever) to change the resolution, or maybe replace the PNG with some other supported extension to save your image in that format.
List of changes in MuPDF 1.10
* Headline changes:
* FictionBook (FB2) e-book support.
* Simple SVG parser (a small subset of SVG only).
* mutool convert: a new document conversion tool and interface.
* Multi-threaded rendering in mudraw.
* Optional JPEG-XR support (not included by default for security reasons).
* Hyperlink support in EPUB.
* Reduced memory use:
* Interface changes and cleanups: