Cambridge English is a unique approach to teaching, learning and assessing English, driven by world-class research and a profound commitment to delivering educational value for the benefit of learners, teachers, educational institutions, employers and society as a whole.
Cambridge English combines the experience and expertise of two world-leading departments of the University of Cambridge -Cambridge English Language Assessment and Cambridge University Press.
Here is the teachers' page:
www.cambridge.org/gb/elt/teachers/?site_locale=en_GB
And the students' link: