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:

• Implemented VScript
  • VScript allows mappers to embed script code (Squirrel3) into maps. This system is already being used for L4D2 and CS:GO maps.
    • Interface with entities and the world like regular Hammer logic
      
    • Simplify things that were previously incredibly complicated/tedious in Hammer logic
      
    • Interact with and control bots, bosses, player attributes, entities, and game state closely, allowing for enhanced, modified or entirely custom game modes
      
    • React to game events and change the outcome of certain things, such as damage calculations
  • More technical info about VScript for Team Fortress 2 is available on the Valve Developer Community
    • https://developer.valvesoftware.com/wiki/VScript
      
    • https://developer.valvesoftware.com/wiki/List_of_TF2_Script_Functions
• Added the ability to change the skybox dynamically using the skybox_swapper entity or SetSkyboxTexture
  
• Added support for custom MvM upgrade files packed into the map
  
• Added point_worldtext, an entity that can show text dynamically, with support for multiple SDF (signed distance field) fonts, multiple colors and a rainbow mode
  
• Exposed several movement related ConVars
  
• Implemented support for func_monitor and cameras
  
• Implemented logic_eventlistener for listening to game events from Hammer logic
  
• Added the ability to pass parameters and delay to MvM populator actions
  
• Improved compile time with VRAD
  
• Special thanks to Jakub and everyone on the GitHub VScript Mega Issue for testing, providing feedback, and submitting requests