This paper deals with the Pascal subroutines for solving certain problems in the interval linear programming, especially with calculating the exact range, i.e. the supremum and the infimum of optimal objective function values of a family of LP problems in which all coefficients in constraints vary in given intervals. A theoretical background of the algorithms and a description of the package is included. An application of algorithms regarding a set of feasible coefficients and the solvability set is described in this paper and numerical experiences are also mentioned. 1.) his research was supported by the Grant Agency of the Czech Republic under the grant No. 201/95/1484.