Fable developer Playground Games has already called on the assistance of some other parties, and following the latest trailer it's now been confirmed Eidos Montreal is helping out.
The studio made it official on social media with the following message earlier on, mentioning how it's been "supporting" development of Fable:
"We're so excited to be supporting the development of @Fable! It's been a blast collaborating with the talented team at @WeArePlayground to craft an unforgettable adventure."
It's not known exactly what it's been working on, but the studio is previously known for the Deus Ex series as well as Shadow of the Tomb Raider and the Marvel's Avengers and Guardians of the Galaxy projects.
News about Eidos Montreal's partnership with Xbox on Fable originally surfaced last November. Fable has also had assistance from Third Kind Games.