The Tau Manifesto is dedicated to one of the most important numbers in mathematics, perhaps the most important: the circle constant relating the circumference of a circle to its linear dimension. For millennia, the circle has been considered the most perfect of shapes, and the circle constant captures the geometry of the circle in a single number.
PerlJedi writes: "A few months ago, a tweet from Randal Schwartz pointed me to a you tube video about "Triangle Parties" made by Vi Hart. Between my nerdiness and my love of math, it was my new favorite thing on youtube. Now, with Pi day coming up later this week, I thought it would be a good time to point people to another of her you tube videos Pi is Wrong, and the website she mentions at the end Tauday with a full explanation of the benifits of using Tau rather than Pi.