I decided to give it go; albeit "standalone", UniPDF is unfortunately not at all portable -- it keeps its settings in a 'config.xml' file in the program folder alright, but at the same time it creates no less than 33 different registry keys (as well as leaving behind folders in %APPDATA% and %TEMP%, which will totally freak stealth purists). A shame, really, 'cause in spite of the lack of OCR capability, UniPDF is a handy, lightweight and efficient offer for document conversion.
[I tried to beat up a quick'n'dirty™ yaP launcher (see https://pastebin.com/bzN4u7QZ), but it is currently unable to delete all those keys (more on that later).]
[EDIT: you can now portabilize UniPDF with http://yap.rolandtoth.hu/configs/UniPDF.ini; my previously improved UniPDF yaP launcher config still is at https://pastebin.com/zzASDydi.]
http://unipdf.com/ wrote:Standalone and easy-to-use, UniPDF performs high-quality conversion from PDF files to word documents (doc/rtf), images (JPG/PNG/BMP/TIF/GIF/PCX/TGA), HTML, or plain text files (txt) in batch mode, with all document texts, layouts, images and formatting ideally preserved.