Co-Masonry?

I was just breezing various items in realation the other night and came across co-masonry. I have heard of it before and also other orgs that fell away from the offical grand lodges.

Can you tell me was co-masonry developed away from the grand lodge or were they F&AM lodges that greq away from the offical lodge?

Are they as active? DO they use the same rituals?

Also any others not seen by the grand lodge but very similar to masonry or once affilated?

Is there any sort of conspiracy line here?