 Εργαστήριο Έρευνας στη Διδασκαλία των Μαθηματικών, A Laboratory for Research in Mathematical Teaching, at the University of Patras (Educational Department), Greece
 Educational Technology Lab, University of Athens, Greece
 ICT in Education, by Aristotle Raptis and Athanasia Rapti
 Lectures, notes and other material, Patras Science Center, University of Patras
 Centre for Science Education (CSE)
 Evangelos Stamatis's Books and publications
 Hellenic Math Society, quite interesting the Digital Library
 Hellenic Math Society  Local Department at Herakleion
 Hellenic Digital Mathematics Library
 mathematica.gr: Lots of mathematical material in a social math network
 Eugenides Foundation
 Thales + Friends
 Ancient Greek Technology, Kostas Kotsanas
 Science Teaching European Network for Creativity and Innovation in Learning, have a look at the European Catalogue of Science Education Initiatives.
 nrich Enriching Mathematics, University of Cambridge
 The MacTutor History of Mathematics archive, School of Mathematics and Statistics, University of St Andrews Scotland
 NCTM (National Council of Teachers of Mathematics)
 Illuminations Math Educational Resourses (NCTM)
 TIMSSVIDEO, a UCLA project: recorded classroom activities in Math and Sciences in various countries as this one in Japan
 101 Questions, real world maths in pictures and videos (by Dan Meyer)
 Great Maths Teaching Ideas, Dan Meyer's blog.
 Cut the Knot, Alexander Bogomolny
 National Library of Virtual Manipulatives, Utah State University
 RITEMATHS Schoool resourses of real world problems, The University of Melbourne
 The Electronic Library of Mathematics (ELibM)
 The Garden of Archimedes, A museum for Mathematics, FlorenceItaly
 MΟΜΑΤΗ, Museum of Mathematics at New York. Have a looka at "Math Monday" in cooperation with The MAKE magazine.
 NASGEm North American Study Group on Ethnomathematics interesting teaching proposals
(like this one in symmetry)
