More recently a new approach has emerged, using "D"-finite functions, which are the solutions of linear differential equations with polynomial coefficients. Most of the elementary and special functions are "D"-finite, and the integral of a "D"-finite function is also a "D"-finite function. This provides an algorithm to express the antiderivative of a "D"-finite function as the solution of a differential equation. This theory also allows one to compute the definite integral of a "D"-function as the sum of a series given by the first coefficients, and provides an algorithm to compute any coefficient.