PEST++ is an object oriented inverse modeling software package written in C++. It expands on the algorithms developed in the widely used PEST parameter estimation code and is designed to lower the barriers of entry for users and developers while providing efficient algorithms. The software is copyrighted but freely available under the GNU GPL3 license agreement.

PEST++ provides several options for performing the forward runs in parallel on multiple computers. These include the “Yet Another run ManageR” (YAMR) which is built into PEST++ and the GENIE run manager which is an external run manager that consists of a file distribution interface, a run manager, and a run executer. Both of these run managers distribute, manage, and execute model runs in parallel on multiple computers runs via a TCP/IP network.