Half Life

The source code for the Half Life/GoldSrc Engine is available from Valve's Github.
The SDK for the game was also released.

Developer Commands

The following commands can be accessed through the game's console,
which itself is accessed with the Tilde key:

• /developer - Output rendering info
• /impulse 104 - Show entities loaded in the level

Regional Differences

The German version replaces many of the human figures with robots.
Moreover, the game is set the lowest violence level by default.