Free Software

"While it doesn’t have all the fancy features of some premium PDF editors out there, it’s also surprisingly feature-rich for a program, making it one of the best free Adobe Acrobat alternatives out there" according to TechRadar review.

Plasfy is an all-in-one, easy-to-use cloud app that simplifies the process of creating professional graphics and designs for businesses.

It runs perfectly in Linux via Wine.

Conversions from Ebook (AZW, CHM, MOBI) to Electronic Publication (EPUB): Page Setup Output Profile: "Generic e-ink HD." Maintains original resolutions of images

In addition to creating forms Master PDF Editor can view, create, modify, sign, scan, OCR and print PDF documents. The free version is not limited, but includes a watermark.