In the beginning, when the Mathematica-users wiki was new, there was an ambition of this site to be THE site for Mathematica users. There was an ambitious effort to provide a number of forums and also to provide a front-end to the MathGroup forum. You might find some historical remnant of this phase here and here. This went up as the sun and down as a pancake, maybe due to spamming problems. There are simply too few Steve Christensens around to take care of such things. Any volunteers around? Please, tell me if my interpretation is wrong!
We could instead see the Mathematica-users wiki as a small part of all Internet resources available for Mathematica users, and then it is logical here to provide links to forums outside this wiki. - Ingolf Dahl (Tue 15 Dec 2009 00:47:50)
(Related pages: Mathematica resources, Links, Packages, and the User web pages.)
Discussion groups, communities and forums
MathGroup (see also Archive and comp.soft-sys.math.mathematica) is a moderated e-mail list and Internet newsgroup, founded and moderated by Steve Christensen. A lot of Mathematica experts hang out, but being moderated don't expect fast response to any questions. Some of the experts prefer good questions and good answers before fast questions and fast answers. More than 100 000 messages in the archive.
sci.math.symbolic is another usenet newsgroup. Your question is posted immediately, as are any answers received. Hence this is a lot faster than using MathGroup, if the experts happen to be online, watching and eager to answer. Here you also find fine offers for sport shoes, handbags, etc., and in Oct. 2009 such subjects dominate. More than 21 000 messages in the archive.
Active_Mathematica A Mathematica users group, with the following points of interest: 1) mathematics 2) fractals 3) surfaces ( minimal, Calibi-Yau, null Ricci and constant curvature, etc.) 4) number theory 5) differential equations ( fractional and partial, etc.) and then more or less anything you can think of to use Mathematica to program. The most active user is Roger Bagula. More than 1200 messages, 71 members.
MathematicaUsers 896 messages since 2002 with a peak in March 2007, 303 members. You must get an Yahoo account first (free).
Mathematica Render is a community dedicated to exploring the power of Wolfram Research Mathematica for technical and artistic design of moving image. The goal is to promote Mathematica examples of dynamic visualizations that can be used in research and education. Started in August 2010. To join the group one needs a Vimeo account which is free.
computerbasedmath.orgis a project to build a completely new math curriculum with computer-based computation at its heart—alongside a campaign to refocus math education away from historical hand-calculating techniques and toward relevant and conceptually interesting topics.