Left 4 Dead 2 mentions (0)

GZDoom mentions (8)

• Is there anything that proprietary software can do and has no open alternative?

  GZDoom for Doom and many other games running on the same engine. Source: over 1 year ago

• John Romero has released a new Doom 2 level for a €5 donation. 100% of the proceeds go Ukraine relief efforts.

  For modern source port check GZDoom https://zdoom.org/index or Chocolate Doom (for higher framerates and stuff) - https://www.chocolate-doom.org/wiki/index.php/Chocolate_Doom. Source: over 2 years ago

• How to I get the ID Build engine?

  Also, if you want to make a shooter like those, you don't really want the original Build engine. What you want is a modern open source implementation of those engines. For Duke-like games you can try https://www.eduke32.com/ (Ion Fury was made on this) , for Doom try https://zdoom.org/index or https://dengine.net/. Source: over 2 years ago

• O3DE: Open 3D Foundation announces first major release of Open 3D Engine

  I don't know, but if you want a retro game you might as well use a retro-engine. Ion Fury (2019) used the EDuke32 engine and there are also modern versions of the original Doom engine, like GZDoom - with modern games like Brutal Doom or SIGIL (2019). Source: over 2 years ago

• Why is this so complicated?

  Because zDoom and GTA anniversary releases are a thing. Source: over 2 years ago