Here's the list of changes to Doom and Heretic:

Changes in 2.05 (over 2.01)

FrontEnd:

• The network window has had a 'names' button added to it, in which you
  may configure player names. Use -pname <myname> for newer games.
  
• Sound setup window now has a 'setup music' option which when enabled
  plays MIDI music whilst setting up the game.
  
• 'No scaled status bar' and 'Open text window' added to Misc window.
  These respectively give an unscaled (ie smaller) status bar, and open the
  new text display window on startup.
  
• 'No startup warnings' added to Misc window, preventing warnings being
  displayed and requiring confirmation during startup.

Game:
 
[General]

• -precachedemo added to ensure that all the demo is precached, for
  demonstration purposes.
  
• Deathmatch games should now always receive the keys they need (problem
  with deciding the keys required on a level)
  
• 24 bit StrongARM code speed up (over 2fps faster on 320x256x256)
  
• Multiple sprite rotation problem fixed (reported in osiris.wad).
  Consequently, rotation problems will now be reported as warnings
  on startup and may be ignored with -noinitwarnings.
  
• Desktop games should now be more playable, especially in network games
  with new key and mouse handling allowing much better control.
  
• Now displays the 'end of game' (ENDOOM) message when you quit (desktop
  only).
  
• Descriptive configuration files are now created.
  
• No longer need to use -devparm to save screenshots in full screen mode.
  
• Now millenium compliant (would have never failed, but was 'wrong')

[Visual]

• Messages window, giving a desktop display of the HUD messages in either
  a fixed pitch font or the system font; useful when messages are turned
  off in the game. Use -font for the font, -nofont for the system text.
  -opentextwin will open the messages window initially. -notextwin will
  disable the window entirely.
  
• Add -moreblood to the 'others' line for more violent blood splatters.
  
• Linear and bi-linear smoothing possible in both 8 and 24 bit for walls
  and objects.
  
• Use -noscaledbar, or select the option from the Misc window, to stop the
  status bar scaling in variable resolution modes.
  
• Smoothing effects are now available from the Options->Display->Smoothing
  menu. There are different capabilities between 8bpp and 24bpp.
  
• Use IDRESAMP to change all the effects in one go.
  
• Use IDCACHE to change column caching. Column caching is the 'StrongARM
  optimisation' and hence will speed up SA redraw if enabled.
  
• Cross hair colour configuration added.
  
• -monsternames can be used to show names over monsters heads.
  
• -diminmenus will dim the background when menus are in use
  
• Iconbar gameplay
  
• Can change resolutions midgame
  

[Networking improvements]

• Changed networking error messages:

  
      NetUpdate: netbuffer->numtics > BACKUPTICS
     becomes
      Tried to transmit more tics than our buffer can handle
   
  TryRunTics: lowtic < gametic
     becomes
      Attempted to run a historic tic
   
  gametic>lowtic
     becomes
      Attempted to run a futuristic tic
    

  
  Which (even if not completely understandable) are less scarey.
  
• BACKUPTICS is now 16, rather than 12; this should speed network games
  slightly.
  
• Option to display scores in a number of forms :

  
     on :
        'level frags' / 'total frags'
     full :
        'level kills' - 'level suicides' / 'total kills' - 'total suicides'
     extended :
        'level kills' - 'level suicides' + 'level monster kills' /
        'total kills' - 'total suicides' + 'total monster kills'

  
  
• Option to details over player heads, for which -allownaming is required on
  the controller for Health, Weapon, and Name
  
• Net 'Net options' menu option, allowing some 'in game' control over
  network game options.

  
     Hold    - if enabled will ignore settings for exiting levels after a
            number of kills, or a number of kills ahead.
     Exit level - exits the level immediately
     End at   - changes the number of kills at which the level ends
     End ahead - changes the number of kills ahead at which the level ends.
    -allowcontrol must be used on the controller for these options to be
    available.

  
  
• -pmi allows 'post mortem invincibility'. This means that after dying, you
  will be invincible for a period. You also cannot shoot for this period.
  
• Can change name whilst in games.
  
• Can change level limitations (eg end at, end ahead) or retain level during
  the game.
  

  Note:
  Network games between mixed 2.01 and 2.02 or later must not use features
  which are not present in the lowest of the versions. It is recommended
  that the lowest DOOM+ version be the controller as this should give the
  most reliable performance.

DOOMFS:

• Better support for Heretic and Hexen WADs
  

NetDoom:

• New driver using new BACKUPTICS.
  
• Added 'List' button to list machines on an Access network.
  
• Added 'drag and drop' facilities for machines in list window (or machine
  names)
  
• 'Auto' button to auto-configure all machines on an Access network.

SDoom:

• New driver using new BACKUPTICS.
  

NetSpec:

• Minor update detailing change to BACKUPTICS.