The paper deals with computer programs for designing heat exchanger networks (HENs). The general information on package HEATREC which is under development are given. Two programs, i.e. TARGET v.2.0 and SIMHEN v.2.0 are described in more detail. The former is for HENs targeting at certain data and the later for HENs simulation computations as well as for retrofitting flexible HENs. The important information on programs are given in the paper, i.e. on methods and algorithms used and way of programs application. A general description of user interface is also presented. Scientific results obtaining during developing, testing and applying the programs are described, too. They deal with methods of targeting for a minimum number of apparatus and a strategy as well as an algorithm of retrofitting flexible HENs by simulation.