We sent our ds to a montessori and it was fantastic, wanted to send him to school, but none in the area did think about moving to ensure his attendance but heyho, bascially;
unlike many educational philosophers maria montessori developed an educational method to implement her philosophy. She wanted her method to be open minded and not a fixed system, she believed in inovation in the classroom and her whole approach to education was in the spirit of constant experimentation based on observations of the child.
There are two main components to the montessori method, 1) enviroment, including the educational materials(which are all natural and found in home enviroments) they dont have plastic or man made products. and 2).the teachers who prepare the enviroment. Maria montessori considered enviroment to play key part in her method. She likes to think of the enviroment as child nourshing where everybody works and learns from each other, including adults learnig from children. Everything is child sized and the teachers work with the children, not just preching at them. The other key to montessori is everything should be 3 dimensional, so the children learn but doing, (great for audiatory learners) and at there own pace, there is no deadlines to meet or exams to sit at certain times. If a child is ready to sit a GSCE at 14 then thats what happens, they can then take the rest at 15 or 16, when they are ready. A pure montessori sometimes don't even sit the SATS (a good thing in my mind).
Hope this helps, sorry it rambles on but it is something i feel very very passoniate about. Montessori is not just learning in a education setting it is a way of life, the children have to be montessori at home as well to reep the full benefits of it. Its just Fantasic.