This is a document file listing the changes in Frazband (compared to
the standard Zangband 2.6.2.) No long explanations, just a list. See
code for details. In reversed chronological order (more or less).
See z_update.txt for details on Zangband 2.6.2:

Frazband 0.4.1
- Fixed display bug in birth routines.
- Added safeguard against getting quests to kill friendlies.
- Touchy monsters now get angry successfully.
- Fixed problems and potential problems with options.
- Touchy monsters now go hostile rather than friendly if
advanced_monst_groups is turned off.
- Townsfolk will now no longer flee into the dungeon.
- Stopped caution messages when taking useless scrolls from home.
- Many players will now never see spontaneous babewyn incursions.
- Allowed protect_savefile to be turned off when importing
0.4.0 savefiles due to it being mistakenly on by default.
- Adjusted difficulty levels slightly.
- Gaining a spell now prompts the player to write it.
- Made duplicate quests very unlikely.
- Players can now see their new magic system spell abilities at the
end of the 'known spells' list.
- Added birth option to hide object graphics at stores.
- Added option to automatically show lists.
- Updated help files.
- Changed some monster rarities.
- Removed the GHB. (Can be uncommented if you want it back.)

Frazband 0.4.0:
- New magic system.
- Old magic system retained as an option, but with modifications.
- Lots of new monsters, removed monsters and modified monsters. 
- Sauron and Morgoth are now the main quests.
- Difficulty system.
- Birth option to be able to reload badly progressing games.
- Improved monster AI.
- Many new types of monster behaviour.
- Modifications to the artifact list.
- Fighter-type characters get more hitpoints.
- Melee skill now boosts AC.
- 'Summon Amberite' spell changed to 'Summon Special', which summons
different (hardcoded) creatures for each monster.
- 'Summon greater demon' spell from Angband restored.
- Levels have a chance of becoming 'babewynified'.
- Some monsters can now 'obfuscate'.
- Uniques which are 'killed' by other monsters now disappear, or 
genuinely die if friendly, to stop the player from being able to kill
one with one spell if a giant fight is going on.
- 'Accelerated development' option added.
- 'Show third party combat messages' option added.
- Friendly monsters can now be disabled.
- Added warning messages when you first spot uniques or
significantly out of depth monsters.
- 'disturb when out of detection range' now prints a message, and
does so regardless of whether or not the player is running.
- Other stuff...