This version of Final Fantasy VI represents a fan translation of the original Japanese release into English. The "En by RPGOne v1.2b" designation suggests a specific translation patch created by the team or individual known as RPGOne, with "v1.2b" indicating a specific version number suggesting updates and refinements over prior releases. The core gameplay remains that of the original SNES release, but the language barrier is removed for English-speaking audiences.  SquareSoft developed the original game.

Final Fantasy VI (Japan) [En by RPGOne v1.2b]

Final Fantasy V (Japan) [En by RPGe v1.1] [Text Hack by Tzepish v1.01] (~Final Fantasy V Spoof)