A new and very exciting (I know, I say that a lot! But many new publications are exciting to me…) issue of ZDM was resently published. This issue (Volume 44, Number 5) is a special issue on: “New Perspectives on the Didactic Triangle: Teacher-Student-Content”. The issue has been guest edited by my friends and colleagues: Professor Simon Goodchild (University of Agder) and Professor Bharath Sriraman (University of Montana). They also wrote the editorial/first article in this special issue, and it has been entitled: Revisiting the didactic triangle: from the particular to the general. The authors of the other articles in the issue is a great mixture of really big names and some younger researchers (upcoming stars if you want) in our field. Here is a complete list of articles and authors in this issue of ZDM, with direct link to the original articles for your convenience:

• Revisiting the didactic triangle: from the particular to the general, by Simon Goodchild and Bharath Sriraman
• Problematizing the didactic triangle, by Alan H. Schoenfeld
• On the instructional triangle and sources of justification for actions in mathematics teaching, by P. Herbst and D. Chazan
• Mathematics teaching development as a human practice: identifying and drawing the threads, by Barbara Jaworski
• The didactical tetrahedron as a heuristic for analysing the incorporation of digital technologies into classroom practice in support of investigative approaches to teaching mathematics, by Kenneth Ruthven
• From the didactical triangle to the socio-didactical tetrahedron: artifacts as fundamental constituents of the didactical situation, by Sebastian Rezat and Rudolf Sträßer
• Kindergarten teachers’ accounts of their developing mathematical practice, by Ingvald Erfjord, Per Sigurd Hundeland and Martin Carlsen
• The mediating role of a teacher’s use of semiotic resources in pupils’ early algebraic reasoning, by Raymond Bjuland
• Mediated action in teachers’ discussions about mathematics tasks, by Claire Vaugelade Berg, Anne Berit Fuglestad, Simon Goodchild and Bharath Sriraman