An update to Team Fortress 2 has been released. The update will be applied automatically when you restart Team Fortress 2. The major changes include:

• Added content and features necessary to begin limited public testing of the TF2 Competitive Mode beta
  • For more information on how you can participate in testing, please visit https://steamcommunity.com/groups/tfcompetitive
    
  • Updated several maps to support competitive mode
• Community request: Added SetPlayerPointsOnDeath input to tf_player_destruction_logic and a PointsValue key field to the item_teamflag entity when used in Player Destruction mode
  
• Fixed Mann vs. Machine Mann-Up victories sometimes failing to take player tickets and reward loot
  
• Fixed security issues when loading certain custom content (thanks to Nathaniel Theis and Simon Pinfold for these reports)
  
• Added the Civilian Grade Stat Clock
  • Applies a Strange Stat Clock to a Civilian grade weapon
    
  • Can be obtained by trading in a combination of 5 Freelance grade or better items through Mann. Co Trades
• Mannpower update
  • Grappling hook movement speed penalty for powered up flag carriers increased by 10%. Flag carriers with no powerup still have no penalty.
    
  • Reflect powerup
    • Removed 25% resistance attribute
      
    • All classes can now have up to 400 health
      
    • Fixed a bug where reflection damage was being calculated prior to distance falloff reduction
      
    • Reflection damage increased from 50% to 80% of damage received
      
    • Fixed a bug where sentry rockets would reflect damage to the owning Engineer rather than the sentry itself
  • Supernova powerup
    • Minimum stun duration increased from 1 to 2 seconds
      
    • Stun duration increased by 0.5 seconds for each additional victim stunned (max 4 seconds)
  • Vampire powerup
    • Melee attack now returns 1.25x damage as health (up from 1.0x)
  • Regen and King powerup
    • Increased the frequency of health regeneration. Rate of heal is increased for Scout and Spy
      
    • Increased metal regeneration amount
• Gift Wrap has returned!
  • Gift wrapped items will be delivered through Steam trading, and are subject to trade holds if the sender doesn't have a Steam Guard Mobile Authenticator
    
  • Items can now be unwrapped by their original wrapper
    
  • Moving forward, only tradable items can be gift wrapped. Items that are currently gift wrapped can be delivered regardless of the tradability of the contents of the gift.
• Giftapults can again deliver items to random players online, but will remain un-craftable
  
• Updated The Bounty Hat, Treasure Hat, and Hat of Undeniable Wealth and Respect to be tradable
  
• Vote kick events now display that target player's Steam avatar
  
• Updated models/materials for Hot Heels, The Trencher's Topper, The Exorcizor, The Mutton Mann, Doc's Holiday, The Cotton Head
  
• Updated the Crusader's Crossbow
  • Added a new shoot sound
    
  • Added a new impact/heal sound when a teammate is healed
• Fixed the Taunt: Kazotsky Kick not hiding the Heavy's weapon
  
• Fixed That '70s Chapeau not being removed when the Sniper taunts
  
• Fixed the Catastrophic Companions hiding the player's hat and headphones
  
• Fixed an LOD issue for The AWPer Hand
  
• Added combat text and hit sounds for damage done to buildings
  
• Added a "Last Hit" sound option to Hit Sounds
  • Triggered when one of your attacks causes the death of a player or building
    
  • Can be toggled in the Adv. Options menu
• Updated the materials for the Panic Attack to support mat_picmip
  
• Updated the Taunt: Zoomin' Broom sound effects
  
• PASS Time update
  • Fixed workshop maps not loading correctly
    
  • Fixed being able to get inside jump pads
    
  • Removed Sandman long-distance steal
    
  • Added experimental cvars for playtesting
• Updated cp_vanguard
  • Removed teleporter exploit on second point
    
  • Various minor fixes (lighting, collision, optimization)
• Updated pl_borneo
  • Fixed an exploit related to the final control point and dropped weapons
• Updated pl_snowycoast
  • Adjusted various spawn point facings to make side exits more obvious
    
  • Adjusted position of resupply cabinet in RED's 1st spawn
    
  • Added ledge to 2nd point flank route window
    
  • Adjusted common sentry nests on 2nd
    
  • Added stronger light to entrance of lower flank route
    
  • Door near RED's first spawn now opens on A capture and closes on final bulkhead opening
    
  • RED no longer get forced respawn when 2nd is captured
    
  • Added minor spawn for RED once 2nd is captured, active until BLU pushes through kennels
    
  • Adjusted timing of flank doors at 2nd and in mines
    
  • Updated door texture for flank exit by 2nd point gate
    
  • Improved defendability and enlarged 3rd point
    
  • Adjusted position of 3rd cap
    
  • Adjusted health & ammo at 3rd
    
  • Updated door texture for flank exit by mines
    
  • Changed a medium ammo pack at last to full ammo pack
    
  • Added door to ledge at last to improve RED defendability (closes when bulkhead opens)
    
  • Added 3rd exit to BLU's last forward spawn
    
  • Improved defendability of ledges at last inside building
    
  • Added new dropdown area to RED's last
    
  • Adjusted lighting in various areas
    
  • Fixed dx settings on light pole props

- Added the GameRules:IsCheatMode() API to detect lobbies with cheats enabled or sv_cheats 1 in custom games.
- Fixed a crash on exit with the Convars:RegisterConvar() API.
- Added the SendToConsole() API to the client.

An update has been released for Left 4 Dead.

- Updated binaries to improve crash reports.

6.86f:

* Deafening Blast's knockback is no longer a hard disable (affected units can cast abilities and items)
* Deafening Blast's disarm portion rebalanced to keep same overall effectiveness as before (it previously applied disarm only after the knockback disable, numbers rescaled to keep same overall duration where they cannot attack)

* Reduced time it takes to start up the game by a second
* Added a custom Poison Touch ability icon for the Darkclaw Emmisary set

An update has been released for Left 4 Dead.

- Fixed an exploit that could allow remote code execution.

An update has been released for Left 4 Dead 2.

- Fixed an exploit where a player could call a vote that would pass immediately without input from the rest of the players.
- Fixed an issue where sounds could start looping on Linux.
- Fixed Steam Controller issues with spectating and MOTD.
- Fixed a bug that could cause some servers to hang on shutdown, causing a temporary reduction in total server capacity after updates.
- Fixed a remote code execution exploit.
- Upgrade OSX SDK version.

* Updated the new Naga Siren set to only require one Infuser (affected users were granted back their extra Infuser)

Winter Treasure IV & The Shanghai Major Compendium

- Reduced the amount of memory used by the game
- Fixed a rare bug where a game would not show up on the live DotaTV games list, which was caused by restarting a failed-to-load lobby within the DotaTV delay window
- Fixed various bugs with replays being unavailable until client was restarted
- Fixed coaches sometimes inadvertently wagering tokens
- Increase framerate and lower memory usage in the Armory
- Fixed the tournament match popup results sometimes having the hero picks swapped between teams
- Fixed a bug where changing wearables while in hero picker screen would cause the hero to stop animating
- Terrorblade items with appropriate detail masks are now affected by gem and arcana colors and textures
- Adding default ambient effects to Terrorblade weapons
- Added Savage Roar animations to Lone Druid Spirit Bears
- Fixed Timbersaw models to show custom Reactive Armor
- Various courier fixes (hitbox adjustments, "haste" run activity fixes, etc.)
- Jakiro and Ogre Magi voices now pan left and right
- Several ability sfx now become audible to enemies after they emerge from FoW. (like Illusory Orb, Stone Gaze, Ghost Ship, etc)
- Fixed a bug with Glimpse sound that could cause it to be really loud
- Disable Help now prevents Io's Relocate and not Tether
- All player-controlled units (instead of only heroes) now respect Fog of War limitations when pathfinding
- Adjusted the pathfinder to limit excessive backtracking
- Quit confirmation popups no longer stack
- Clinkz's Skeleton Walk and Tusk's Walrus Punch effects no longer play at the caster's last known position when they are in fog of war
- Fixed Arc Warden's Tempest Double health cost being damage rather than a proper hp cost
- Fixed minimap jumping back to the left side of the screen if you change resolutions with minimap set to the right side of the screen

Workshop Tools
- Added support for editing more types of attachment points when submitting items
- Added the ability to set the fog depth on water materials
- Fixed bug where overlays did not work correctly on scaled models
- Enabled workshop default ambient effects model for Terrorblade's weapon
- Made map compile respect smoothing angle and edge hardness between tiles

New Heroes on the Dota Workshop
- Arc Warden
- Shadow Fiend
- Winter Wyvern
- Zeus
- Undying

Workshop Hero Files Updated to Source 2
- Broodmother and Spiderling
- Lina
- Omniknight
- Pugna and Nether Ward
- Sniper

Ability Items Added to the Workshop
- Terrorblade Demon
- Clockwerk Cog

New and Updated Workshop Reference Files can be downloaded at http://www.dota2.com/workshop/requirements

Winter Treasure III Released: http://blog.dota2.com/2016/02/winter-treasure-iii/

- Fixed the Fog of War culling radius on some item-granted teleport effects to match the default effect size.
- Fixed an occasional crash on Mac OS X when certain keys were pressed.
- Spectre's Spectral Dagger no longer procs Lotus Orb during secondary collisions.
- Fixed a rare crash when popping up an inventory item tooltip.