Version 2.4 (to come)

o Optional content groups now preserved when merging / stamping pages
o Vendored in tiny_json from Yoshihiro Imai via Jan Furuse
o New -labels-progress option to improve page labels interface
o New options -output-json et al. to export PDF files in JSON format

Version 2.3 (patchlevel 1, December 2019)

o Fixed bug which prevented -info working on encrypted files
o Allow -shift with -add-text for additional adjustment
o Prepend and postpend directly to page content streams

Version 2.3 (October 2019)

o Directly set and remove Trim, Art, and Bleed boxes
o Dump attachments to file
o Extended bookmark format, preserving all bookmark information
o New -pad-with, -pad-mutiple-before options
o Set or create XMP metadata
o Remove graphics clipping
o Extended support for reading malformed files
o Embed missing fonts by calling out to gs
o Set bookmarks open to a given level
o Create PDF files from scatch
o Remove single images by name
o Add trim marks

Version 2.2 (patchlevel 1)

o Fix for inability to read null objects in streams
o Workaround for Adobe "Error 21" on re-saving encrypted files
o More efficient bookmark operations on files with many pages
o New operation -hard-box to clip contents to a given box

Version 2.2 (March 2017)

o Perform arithmetic on dimensions when specifying size or position
o Add simple rectangles to PDF to blank things out
o Stamping operations now preserve annotations
o Decryption fully on-demand for speed.
o -keep-l keeps existing linearization status
o -remove-dict-entry to remove the contents of a dictionary entry
o -topline in addition to -midline
o -producer and -creator may be used to alter producer and creator
in conjunction with any other operation
o -topline and -midline now apply to stamps
o -list-spot-colours
o -bates-at-range and -bates-pad-to
o -print-page-labels
o -squeeze replaces smpdf
o Preserve more sharing of data when doing merges and page alterations

Version 2.1 (December 2014)

o Encryption now much, much faster
o Faster parsing of delayed object streams on large files
o -decompress now leaves object streams decompressed
o Select pages by landscape-ness or portrait-ness in a page range
o New -open-at-page and -open-at-page-fit option to set the open action
o New -recrypt option to re-encrypt output
o Reads XMP metadata and outputs it on -info
o New -center position for text
o -stamp can now use positions, just like stamping text
o Better handling of permissions for files with user passwords
o Linearization excised
o Can encrypt or recrypt output of -split and -split-bookmarks now
o -args replaces -control with better behaviour
o Can scale a stamp to fit before stamping with -scale-stamp-to-fit