Epistat Statistics Package 3.3 (1986)

Statistics package from PC-SIG disk 88. One of the first statistics packages available for microcomputers. Quite cheap and bug-free. Written entirely in BASICA (no small feat). By Tracy L. Gustafson, M.D. Lots of references to it in Google Scholar, apparently been used by a number of researchers.
Described in DIZ:
This package contains a set of routines for use in analysis of small data sets, and is meant to be used by a person well-versed in math and computer operations. This is a fairly complex disk and is not recommended for the casual user. But for those with an interest, it can be of great help.