I’ve been using PDF Studio since version 6.62. Back then, years ago, it was IMHO the best of the many PDF editors on the market (including Acrobat-by a mile!), although it did have a few head- scratching shortcomings, including the absence of an undo function (!?) and occasional crashes when working with multiple PDF files simultaneously. These and other glitches seem to have been fully corrected, however, by a series of updates through version 12 and, most recently, to PDF Studio 2018. In addition, new functionalities and design improvements, including a totally revised navigation ribbon, have made working with the software faster and more intuitive. My main use of PDF Studio over the years has been in studying, annotating and playing classical piano music from pdf keyboard manuscripts. The software lets me:

• remove and modify manuscripts’ piano fingerings to suit my hand size and interpretation of the music,

• highlight manuscript areas that I need to focus on by overlaying them with highly transparent rectangles of pale color,

• attach audio files to the pdf manuscripts of the music I am playing so I can hear how various performers interpret the music while I am studying and playing it,

• insert bookmarks into the manuscripts to enable navigation through compositions’ sections,

• add notes directly on pdf manuscripts about my interpretation and performance of the music,

• use PDF Studio’s many other powerful features to enhance my piano studies and playing.

For years I’ve been content to use my old version 6.62, which still remains among the best PDF editors available. But at this point it’s clear to me that PDF Studio 2018 is far and away the most flexible and powerful tool for building highly creative PDF editing applications that can enhance whatever kinds of computer work one undertakes.

The huge opaque water marks diagonally across each page makes it quite unusable even for private use. So you have to buy one.

Info for linux users only:

I have been hunting around for a free linux pdf editor that can produce 'permanent' bookmarks, comments and annotations and I am shocked that its so difficult to find one. In windows there are so many (pdf xchange viewer).

jpdfbookmarks can add bookmarks but not anything else.

okular, one of the best readers cannot do permanent annotations, bookmarks, etc. The ones it adds are stored in its settings. so when we send the file to someone, they won't get it.

If someone finally finds one, please please tell me. :-).............