An experimental interval arithmetic package in Maple. We describe an experimental arbitrary-precision interval arithmetic package written for the computer algebra system Maple. The functions implemented are those of the proposed Basic Interval Arithmetic Subroutine (BIAS) library. We give here an overview of the package design, some examples of the usage and code, and a report on our experiences. The package will be made available under the name INTPAK from the Maple share library (anonymous ftp to daisy.uwaterloo.ca in a subdirectory of the directory maple) at a future date.