Chebfun is a free/open-source software system written in MATLAB for numerical computation with functions of a real variable.

Thus, for example, whereas the SUM command in MATLAB adds up the elements of a vector, the SUM command in Chebfun evaluates a definite integral.

The package aims to combine the feel of symbolic computing systems like Maple and Mathematica with the speed of floating-point numerics.

[2][3] The Chebfun project is based in the Mathematical Institute at the University of Oxford and was initiated in 2002 by Lloyd N. Trefethen and his student Zachary Battles.

Chebfun2, a software system that extends Chebfun to two dimensions, was made publicly available on 4 March 2013.