- Patch #147310 by c960657: added tests for private files, fixed a problem with private files and minor improvements.

#323112 by dmitrig01, kkaefer, quicksketch, frando and many many more: Now presenting... Vertical Tabs. Fantastic new UI improvement for node forms and hopefully more in the future.

- Patch #319356 by recidive: clean up hook_nodeapi_ fucntion signatures and documentation because of previous node API clean-ups.

#313213 by maartenvg, Gábor Hojtsy: Add a 'title' attribute for permissions to allow for localization of permission names

#142995 by dopry, drewish, quicksketch, jpetso, and flobruit: Adding hook_file_X(). This is an enabler of lots and lots of goodies. See CHANGELOG.txt for more. Awesome work, guys. :)

- Patch #161301 by Eaton, Sun, moshe and webchick: make checking for node edit forms easier. DX improvement.

#308434 by drewish, dopry, quicksketch, aaron, jhedstrom, and friends: Massive file.inc cleanup aaaaaand... tests! Yay! :D

- Patch #252013 by Eaton, pwolanin, Susurrus et al: drupal_render() now printes #markup, not #value.

- Patch #247095 by drewish ad flobruit: upload module performs permission checks on files it doesn't control.

  et al.  Can you say 'registry'?  Drupal now maintains an internal registry of
  all functions or classes in the system, allowing it to lazy-load code files as
  needed (reducing the amount of code that must be parsed on each request). The
  list of included files is cached per menu callback for subsequent loading by
  the menu router. This way, a given page request will have all the code it needs
  but little else, minimizing time spent parsing unneeded code.

- Patch #245115 by kkaefer, John Morahan, JohnAlbin et al: after a long discussion we've decided to make the concatenation operator consistent with the other operators.

- Patch #30984 by webchick, keith.smith, kkaefer, Crell et al: provide descriptions for permissions on the permission administration page.

- Patch #219883 by gdevlugt and webernet: files attached to newly created nodes are listed despite unchecking list option.

#200069 by keith.smith: new standard for 'more information' links in module help texts, as the handbook we referred to before was renamed

#197297 by DanW (as GHOP 17), and keith.smith: clean up lots of help texts, update to drag and drop functionality, drupal.module removal, etc