Site Milestones
June 2010: Math.SE was proposed on Area 51 by Dan Dumitru.
July 2010: Math.SE enters the beta phase. The first question was What Does it Really Mean to Have Different Kinds of Infinities? At least 60 users actively participated in the private beta (July 20-27). The most active users during the public beta phase (July 27-October 25) are listed here.
August 2010: $1000^{\rm th}$ user joined.
October 2010: The site graduates from beta and gets its own design.
November 2010: First "Great Answer" badge awarded to Qiaochu Yuan for Mathematical difference between white and black notes in a piano.
December 2010: First "Great Question" badge awarded to user Chris for Why can you turn clothing right-side-out?
January 2011: $10000^{\rm th}$ answer posted.
April 2011: $10000^{\rm th}$ question posted.
August 2011: $10000^{\rm th}$ user joined. Is this Batman equation for real? becomes the first question with $100000$ views.
October 2011: First paper accepted for publication (also here), based on a collaborative effort between math.SE users Listing, Peter Taylor, J.M., and Mike Spivey on Listing's question - $n$th derivative of $e^{1/x}$. Paper published in the February 2013 issue of Mathematics Magazine.
December 2011: $\TeX$ support for chat is introduced by robjohn.
January 2012: Math.SE becomes the first SE 2.0 site with a 100K user (Arturo Magidin), excluding Stack Overflow.
August 2012: $100000^{\rm th}$ answer posted. J.M. is the first user to vote $10000 $ times.
January 2013: $100000^{\rm th}$ question posted: Continuity of analytic function implies convergence of power series?
February 2013: The homework tag becomes the first tag to reach $10000$ questions.
March 2013 was the first month with over $10000$ questions asked.
July 2013: The site becomes third on SE in the number of questions; first time an SE 2.0 site overtook a member of the original trilogy (ServerFault).
October 2013: André Nicolas is the first user to reach 200K reputation.
November 2013: The site becomes second on SE in the number of questions, trailing only StackOverflow.
January 2014: $100000^{\rm th}$ user joined.
June 2014: The Official Math.SE Blog launched.
August 2014: The homework tag is burninated and blacklisted.
October 2014: Post $\#1{,}000{,}000$ appears, an answer by mjqxxxx.
November 2014: Michael Hardy is the first user to make $10000$ edits. André Nicolas is the first user to reach 300K reputation.
January 2015: Qiaochu Yuan is the first user to collect $1000$ (non-unique) badges.
October 2015: $500{,}000$ questions; the mark was reached on October 10.
January 2016: The Student badge becomes the first badge to be awarded $100{,}000$ times; the mark was reached on January 4.
December 2016: The $1{,}000{,}000^{\rm th}$ answer was posted.
October 2018: The $1{,}000{,}000^{\rm th}$ question was posted, titled: Separation Properties in Topology. Math.SE is the first SE 2.0 site to reach 1 million questions.
February 2023: The number of undeleted users surpasses 1,000,000.