I went to a Montessori school from pre-k to 5th grade. The school I went to was just completely different from any public elementary school I have visited in this country.
Instead of a one-size-fits-all mentality for education, each teacher developed a work-plan for each student that he/she was to complete at the end of the week. There were no desks, but workmats that we could arrange on the floor or at a table. Everything we did had to be kept on the workmat, but allowed for freedom of working wherever in the classroom. There were 9 week assessments which determined our progress and helped establish the pacing of our work-plans. Almost everything was independent. Teachers only taught in small groups of similarly leveled students, but this was maybe twice a week. They seemed to serve more as facilitators of learning, not leaders.
A similarity to this article was that second/third languages started early. I went to Montessori only speaking Persian and a little English, but within 1 year I was also enrolled in Spanish, and 3 years later in French. I have since forgotten the French--there are few to speak it with in Alabama, but I have retained decent fluency in Spanish. We had little in the way of sports aside from PE, but we had art classes twice a week (visual arts once on tuesdays and musical arts on thursdays). We also had computer training from a very early age; I remember being on the early internet waaaaay back in 1995 when I was 7.
Classes were interestingly set up as well. In one classroom there were 3 grades of students with two teachers. I think there were maybe 40 kids spread amongst the years. We stayed with the same teacher for 3 year blocks. My experiences were Pre-K and Kindergarten / First-Third Grades / Fourth-Sixth Grades. Interaction and cooperative learning between both grade-level and skill-level was encouraged, with the idea that one could only master the material if you could teach it to someone else.
Any further questions? I'll try to answer to the best of my ability.