Final Cut Pro 7 to FCP 10

I'm making a movie with an "oldschool" director, he's working over FCP7 and I have FCP 10, is it possible to share our save files ? we have the exact same folders and .Mov files with the same name !

You can do that operation ONCE, if his edit is not too complicated.

With 7toX (from FCP7 to FCPX)

or

X2CC (from FCPX to FCP7)

You cannot make it a permament workflow. You will need to choose what you use for the project.

I can tell you in the end it will be such a royal PITA, it won't be worth the effort. Both of you need to get on the same NLE. Going between them will really slow you down, and not everything translates over. Been there, done that, will never touch a project that uses multiple NLEs. Not for all the money in the world.