You are talking about the Gigas like if there are many versions of this warship. The model is changed?
Ok I'll break the rule slightly
Gigas Release 1 2000-2001: Was a big modified Sathanas, the Gargant is based of the final version of this release version. There was two versions, a demo one with limited turrets and the final version with around 90 or so turrets.
Gigas Release 2 2002-2003: The R1 Gigas. Two versions, the SCP patch is a fix for some errors found later in the original version
Gigas Release 3 2003-2005: The 'current' Gigas, you've probably seen a few shots of it on the website. This is the current model you know about. This is the only unreleased version of the older models, and I don't plan on releasing it.
Gigas Release 4 2005-2006: The current model, blurred so you can't see it correctly. Keeps the Rakshasa style front of R2 and R3, but looks far more Shivan than those two versions. Turret count upped to match the improved Icanus, and has the highest polygon count of all Gigas versions.