The software package SPLINEPAK was designed as a supplement to the book ”Spline Functions: Computational Methods” by Larry L. Schumaker. The package is meant for educational purposes only, and no commercial use of the code is permitted. It contains 231 Matlab p-files which code the basic functions described in the book for carrying out various computations with splines. The package deals with computational methods for splines defined on intervals, rectangular partitions, planar triangulations, and triangulations on the sphere. The focus is on interpolation, data fitting, and the numerical solution of boundary-value problems using splines. However, it is expected that the library of p-code in the package will also be useful in solving a variety of other computational problems involving splines.