The Xeno franchise is an overarching collection of role-playing games directed by Tetsuya Takahashi, released by several different publishers on a variety of platforms. The first game, Xenogears, was developed for the PlayStation while Takahashi and his wife, fellow game-designer and writer Soraya Saga, were employees of Squaresoft (now Square Enix). Upon leaving Square, Takahashi founded Monolith Software and partnered with Namco as part-owner and publisher. While part of Namco, Takahashi's team began development of Xenosaga, which is set in the same universe as Xenogears, but takes place in a different period of time. The series was meant to tell its story over the course of six games. However, disagreements with Namco over the direction and accessibility of the series resulted in the story being truncated down to a trilogy.
After the completion of Xenosaga, Namco eventually sold its stake in MonolithSoft to Nintendo, for whom Takahashi began development of an RPG originally entitled Monado: Beginning of the World. However, he later elected to change the name of the game to Xenoblade (Xenoblade Chronicles outside of Japan) due to its thematic similarities to his previous Xeno- titles. The game was followed up by a more open-ended, mecha-centric title called Xenoblade Chronicles X on Wii U and is a spiritual successor to the original Xenoblade Chronicles rather than a direct sequel. However, only two and a half year's after X's release, a numbered sequel, Xenoblade Chronicles 2, was released for Nintendo Switch.
The prefix "Xeno" is the Greek prefix for foreign. Takahashi stated that he uses this prefix as both a signature for the style of game that the entry belongs to, and because as humans our first instinct when coming into contact with foreign life is to create conflict.