The major changes include:
L4D 360:
- Added “The Sacrifice” content.

L4D2 360:
- Added “The Sacrifice” content.
- Added “No Mercy” content.

- Game Play
• Bullets that first pass through an infected character before striking a Survivor are now ignored as friendly fire.
• Fix for survivors speaking The Passing Finale lines in other campaigns.
• Added a setup timer to Versus Survival
• Fixed bug in Versus-Survival where a team could get 5 survivors
• Removed Defibs and First Aid Kits in Realism Versus. Survivors start with a First Aid Kit, but all world spawns are disabled.
- UI
• Added vote option to enable All Talk in Versus.
• Added vote option to Restart Chapter in Versus.
• Added the ability in the lobby for all players to vote on starting the game.
- Versus
• Charger now receives 300 points for any Survivor that is insta-killed.
• Charger now receives 100 points for any Survivor that is insta-incapped by a charge.
• Any infected that causes a Survivor to stumble into a “ledge hang” situation will receive 50 points.
• Tanks go into a stasis when they spawn and leave stasis when the human player takes over.
• Tanks in stasis are invisible but still show a glow to the infected team.
• Tanks do not attack when they are in stasis.
• Tanks in stasis cannot be set on fire or damaged.

L4D PC:
- Fixed a few third person camera cheats.
- Added VPK audio cache support.
- Added “The Sacrifice” content.
- Added Versus Multi-Map Scoreboard
- Added the L4D2 Mounted .50 Cal
L4D2 PC/OS X:
- Game is fully playable on the Mac platform.
- Fixed a few third person camera cheats.
- Added “The Sacrifice” content.
- Added “No Mercy” content.
- Versus: Infected players will get a respawn time reduction against teams that rush.
- Removed need for Left 4 Dead 2 Add-on Support for Community Campaigns

21/07 – TF2

An optional update for Team Fortress 2 is now available.  Here are the specific changes:

Server Browser:

- Fixed the server browser not saving filter settings properly.

Team Fortress 2:

- Fixed a speed exploit related to benchmarks.

- Fixed Parasite hat not being posed correctly on class loadout panels.

- Fixed a level change crash.

Jason

21/07/2010 – L4D2

Updates to Left 4 Dead 2 have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Left 4 Dead 2

- Added additional protection for critical files

- All add-on files will be loaded when connecting to a Non-Official server regardless of game mode

- Only approved custom maps will be loaded when connecting to an Official server

- Player’s can print the contents of the consistency list with “cl_print_consistency_list”. If the server has sv_consistency disabled, the user will be notified when they attempt to print the list

- Improvement to Hammer load times

22/07/2010 – CS 1.6

A beta update to the Counter-Strike 1.6 dedicated server is now available.  To access the beta, run the update command with “-beta hl1beta”.  The specific changes include:

- Potential fix for svc_bad network errors (thanks to Sorin)

Jason

22/07/2010 – L4D2

The Linux dedicated server for Left 4 Dead 2 has been updated.  The specific changes are:

- Fixed Linux dedicated server crash when path to dedicated server installation included uppercase characters

Jason

23/07/2010 – Counter Strike Source

A required update for Counter-Strike: Source is now available.  The specific changes include:

- Added Steam Clan Tag support ( Set yours in Options->Multiplayer->Advanced )

- Added new achievement “CLAN WARFARE”: Win a match of at least 10 players where the entirety of each team is composed of a single clan.

- All weapon fire rates now tuned to match their pre-update, tickrate 100 equivalents. (http://forums.steampowered.com/forums/showthread.php?t=1368659)

- Added automatic server tagging for some server convars ( “mp_startmoney”, “mp_friendlyfire”, “bot_quota”, “sv_nostats”, “sv_allowminmodels” )

- Fixed some issues for players who were experiencing stat corruption.

- Fixed several server crash exploits.

- Fixed server commands “sv_disablefreezecam” and “sv_nowinpanel” not working on dedicated servers.

- Adjusted some DX9 shaders to look more like their DX8 counterparts, e.g. flashbang effect.

- Community Requests:

- Fixed entity I/O messages “OnPlayerPickup” and “OnPlayerUse”.

- Restored UTF-8 support in the console.

- Added env_hudhint entity, for use in custom maps (The allplayers flag must be set for the hint to work in Counter-Strike.)

- Added client convar “sv_hudhint_sound” to turn off emit sound for hud hints.

- Restored the “cl_minmodels” client convar.

- Added server convar “sv_allowminmodels” that allows them to prevent clients from using “cl_minmodels”.

- Added a button to Options->Multiplayer that allows players to reset their in-game stats.

- Note:  Due to the nature of stats corruption, it is not possible to automatically fix all types of stats (such as weapon statistics reflecting usage of the wrong weapon).  Players who suspect their stats are incorrect and wish to start fresh may want to use the new stat reset feature.

Jason

A required update to Left 4 Dead 2 is now available.  Please run hldsupdatetool to receive the update.  The specific changes include:

- Fixed original survivors cheating in Bleed Out mode by throwing first aid kits

Jason