They are a global evangelical ministry. www.acts3.org
The only reason that I know about them, is that my wife and son accompanied an Acts III group to Malawi (Africa) this past summer to help set up a Montessori school at an orphanage (my wife is a Montessori teacher). They were told that being non-religious was not a problem - I think that meant that they would be happy to have the chance to convert my 10 year old son. He refused to let them baptize him, told the ministers that he was a Secular Humanist, and since he lived his life by The Golden Rule, was happy as he was. :D
After that, my wife overheard others in the group wondering what my family were doing there, as they certainly weren't part of 'them'. :grr: Gee, maybe they were there to help people for the sake of helping them?
They ended the trip feeling a little bitter about that, but really happy with the classroom. My wife was single-handedly responsible for creating or buying almost all of the classroom materials. Quite a few pics of the classroom among these pictures on the blog written by the teacher that is staying there for the schools first year.
http://www.acts3.org/blog/montessori.phpSorry for the ramble, I got off of your original question just a bit.
Oh, here is the Golden Rule graphic that my son insisted upon framing and hanging over his bed: