Rather than requiring expensive first-party software for edits or a source file, PDFpenPro allows you to quickly and easily edit the documents, changing text, highlighting segments, and adjusting on-page elements. It's not as powerful as the full Acrobat suite, but it's close and it's a lot more accessible. When you open PDFpenPro, you're asked to register for ease of updates and file saving, but it's not required. You can then immediately start opening and editing files.
This article looks briefly at its main features and limitations, running version PDFpenPro is designed primarily as a PDF editor, with a friendly modern interface based on highly-configurable toolbars. Annotation tools include a marvellous user-extensible library of marks, which includes a full set of traditional editing marks.
PDFpen & PDFpenPro 9 – What's New