Tau Canon or Gauss Gun?

[Ikagura]

Why this weapon has two separate names?

[The Weed Monster 420]

Perhaps they were originally going to be two separate guns, however, they ended up being so similar that they just decided to merge the weapons into onw

[cambreaKer]

it was called gauss gun internally in hl1 and i don't remember it was ever referred to by name in that game, in hl2 they called it the tau cannon and it it's stuck ever since, and even in the anniversary update for hl1 they made it so it says tau cannon instead of gauss in the multiplayer killfeed

[MisterMan]

The name "Gauss Gun" was a older name from the weapon's early stages, the name "Tau Cannon" is the true and canonical name for it.

[Chimz]

And as a PS to what MisterMan said, a real Gauss Cannon is different to this gun. A gauss gun is a coilgun, using magnetic forces to launch steel projectiles.
What you see in game is actually a Tau Cannon and is why the name was corrected in HL2.

[dave.iceman42]

Maybe Tau Cannon is a brand name of Gauss Gun. Or vice-versa. LOL
/kidding.

[Cat]

Many guns have more than one name like gluon/Egon, hornet gun/hivehand, 9mm pistol/Glock 17, etc. They just had different ideas to name them.