Freeware Snapfiles

Portable Document Format Software

Ghostscript (engine of creating .PS and .PDF)
Make PDF (front end for Ghostscript and turning postscript .PS files into .PDF)
GSView (PS and PDF reader)
Nitro Reader (PDF view and writer on .PDFs, good for adding visual signature; shows result; relies on internal fonts; cannot guarantee font view of receiver)
Foxit PDF Reader (PDF view and writer; shows text behind scanned image PDF)
PDF-XChange (PDF view and writer on .PDFs, menus that nag, not so good for printing)
Sumatra PDF (mark up recognition best for printing I think)
Tomahawk (Wordprocessor: exports writing and arrangement to .PDF, extracts PDFs to text and images, does not write over .PDFs)
PDFill Tools (free with limited software, but useful for these)
PDF 24 Editor (It isn't: it converts to .PDF with its printer; extracts from .PDF)
Nuance Reader (PDF view and allows minimal changes, online conversions from .PDF)
Hexonic PDF Split and Merge (Does as in the title)
PDFMerge (Does as in the title)
Separate PDF Pages (Does as in the title)
Tweak PDF (Affects Properties and immediate appearance on saved copy)
Acrobat Reader (Standard slow viewer)

Portable Document Format files are a formatted presentation of print to file files, thus they show what would be seen on paper.
They used to be secure and unalterable. These days writing, mark up text and images can change what is on them, and usually involves extra .XML overlay placed text and objects. Older readers cannot see such additions. Text is usually editable by double clicking on it.
Overlay text looks like HTML but is XML that can position text. Overlay adds to the file, say at the top, but the result viewed is displayed in position in the file. Look at a .PDF file in a Hex viewer to see where added text is actually placed and the coding used.
Government and business have used .PDF files to fix an appearance, without risk that Microsoft Word or Microsoft Excel file's settings on another computer will change the appearance of the form, or how the browser interpretation and size alters a web page. However, some Ghostscript created .PDF files do not carry internal fonts and can change font appearance on view depending on fonts available.
Some .PDF printer drivers use Ghostscript and this needs downloading first. Other printer drivers do everything built in. Creation of .PDFs also exists in some programs, for example Open Office and Musescore.
Many a print to file becomes "Postscript" (sometimes .PS) via a postscript including printer (a number come with the Windows OS) and this .PS then is made into a .PDF (Portable Document Format) using something like the front end visual menu MakePDF guiding Ghostscript.
The best viewer used to be PDF XChange, which allows typewriting on to the .PDF page. It now iritates me with menus for a paid version. Foxit Reader caught on and so has Nitro PDF and Nuance PDF. After editing, text can be moved around. Clicking inside the block of text makes the text open to be editied again.
Printing to paper is best done with Sumatra .PDF, the fastest, simpler, reader. It sees all the XML mark up, properly, and produces a clean, non-negative output.

 

Adrian Worsfold