Developer commentary

Commentary nodes are spinning talking notes that the Valve team talks about how or why they made a map, an enemy, a character, or a storyline idea and also talk about what happened in the earlier versions of areas. They were introduced in Half-Life 2: Lost Coast, then added to Episode One, Episode Two, Portal and Team Fortress 2.

To listen to a commentary note, the crosshair must be put on any floating commentary note, then the "USE" key ("E" by default) must be pressed. To stop it, the same key must me press on the note again. Sometimes the notes can take control of the game and show the player some areas or other things. While a commentary note is played, the game is temporarily stopped.

People of the Valve team who can be heard

 * Viktor Antonov
 * Charlie Brown
 * Ted Backman
 * Kelly Bailey
 * Aaron Barber
 * Ken Birdwell
 * Greg Cherlin
 * John Cook
 * Dhabih Eng
 * Erik Johnson
 * Ido Magal
 * Gabe Newell

Trivia

 * Gabe Newell always makes the first commentary.