We implement the $W$-function approximation scheme described by the authors [ibid. 21, No. 2, 161--171 (1995; reviewed above)\rbrack. A range of tests of the approximations is included so that the code can be assessed on any given machine. Users can calculate $W(x)$ by specifying $x$ itself or by specifying an offset from $-\exp(-1)$, the latter option necessitated by rounding errors that can arise for $x$ close to $-\exp(-1)$. Results of running the code on a SUN workstation are included. (Source: http://dl.acm.org/)

This software is also peer reviewed by journal TOMS.