3Blue1Brown

Grant Sanderson, better known online as 3Blue1Brown (or 3b1b), is an American YouTuber who uploads animated educational videos about advanced maths.

Videos
Grant's videos are typically either lessons on topics such as linear algebra, Fourier transforms, or calculus, or videos about maths problems. He creates most of the animations programmatically, using a python library named "manim". He has also used Grapher for a number of 3D animations. Most of the music in his videos is by Vincent Rubinetti.

History
Grant created his channel on March 3rd, 2015, and uploaded his first video on March 5th, 2015. He began "forging a less traditional path into math outreach", thanks to Khan Academy's talent search. This led him to make videos and write articles for them in 2015 and 2016, as their "Multivariable calculus fellow". After that, he began focusing his full attention on 3Blue1Brown. He uploaded his channel trailer on November 25th, 2016. He uploaded his most popular video on October 5th, 2017.

Origins of username
His logo and username are a reference to his right eye, which is three quarters blue and one quarter brown, due to sectoral heterochromia. He has stated that "it has a way of putting a genetic signature on (his) videos".

Trivia

 * He studied maths at Stanford, with "a healthy bit of seduction from computer science along the way".
 * He is one third of the podcast "Ben, Ben, and Blue", along with Ben Eater and Ben Stenhaug.