Anyone who is interested in the best ways to teach and learn mathematics ... at every level. This includes teachers, from primary to secondary; lecturers at college and university; private tutors; educational psychologists; and anyone studying to be any of these. And anyone else who is interested. The term 'mathematics' is defined liberally, to include pure and applied mathematics, statistics, formal language theory, algorithms, and logic.
We will meet to hear speakers from the Mathematical Association, the Association of Teachers of Mathematics, university researchers reporting on their own research in this field; and each other. We will also have meetings without outside speakers, to discuss interests of concern among ourselves, such as new developments in the Mathematics curriculum and how to teach it. We can invite speakers on any subject which interests us, even if it's not directly related to teaching -- such as someone reporting on recent developments in Number Theory, or the application of statistics to pattern-recognition in Artificial Intelligence.
We can also exchange resources, such as handouts, Powerpoint slides, videos, etc. -- mainly in digital form. If someone else has developed a Scheme of Work, a good slideshow on Completing the Square or Adding Fractions, a set of sample Common Entrance Scholarship maths papers from schools around the country, and is willing to share them, why re-invent the wheel?