June 20 sees Iron Maiden at the top, along with Rob Zombie and Queensryche on the main stage. Main Stage two has Slayer, Trivium and Sepultura.
June 21 has Aerosmith, Deep Purple, Status Quo and Skid Row on the main stage, with Avenged Sevenfold, Soulfly and Hatebreed on Main Stage 2
The final day sees Black Sabbath at the top of the bill on the main stage, alongside Soundgarden, Megadeth and Alter Bridge. Main Stage 2 has Emperor, Iced Earth and Behemoth.
Over and above these acts, there are bands playing each day on the Altar, Temple, Valley and Warzone stages.
More acts on the bill are expected to be confirmed.
Again, it compares well with the UK's biggest rock festivals Download and Sonisphere, with - it could be said- the best acts that feature across these two events.
No Metallica obviously, but no shortage of first class bands at Clisson nonetheless.