I would like to announce the Official Release of PGENESIS 2.4 along with a significant update to GENESIS 2.4. GENESIS is implemented with an object-oriented design that groups related object and command definitions into separately compiled libraries. Parallel GENESIS (PGENESIS) adds a library with a "postmaster" object to the usual usual GENESIS objects and commands. This allows a GENESIS simulation (e. g. a large network model) to be split into many MPI processes that communicate through the postmaster. The November 2014 release of GENESIS 2.4 was intended to be the last packaged GENESIS 2 distribution for download from the GENESIS web site (http://genesis-sim.org/GENESIS). As GENESIS is user-supported, rather than centrally developed, updates to GENESIS and PGENESIS are now obtained from the Repository for Continued Development of the GENESIS 2.4 Neural Simulator (https://github.com/genesis-sim/genesis-2.4). The object-oriented design and organization not only fosters the community development of neural models, but of the simulator itself. This new mutually-developed release of PGENESIS is such an example. As users have continued to contribute new libraries and improvements, there has been an increased use and extension of GENESIS and PGENESIS for its original purpose of realistically modeling cortical networks of multicompartmental neurons on parallel computers. Recent updates to GENESIS and a merge of the GENESIS/PGENESIS development branch from the U.S. Army Research Laboratory have addressed a number of issues in order to increase its scalability for modeling very large networks on high performance computing resources, allowing for models of millions of neurons. These improvements have made it necessary for a new release of a combined package of the May 2019 GENESIS 2.4 Update and the PGENESIS 2.4 Official Release.  Information about this release and downloads are available from the GENESIS web site (http://genesis-sim.org/GENESIS). The official release of PGENESIS 2.4 is much improved from the December 2014 preliminary release. Updates of GENESIS since the 2014 release allow the fast "hsolve" solver to be used with new synaptic plasticity models and measurements of cortical field potentials. The efficient delivery of spike events when hsolve is used with large network models results in increases in simulation speed by factors of 10 to 20. This release of PGENESIS 2.4 is also now available for running large-scale network simulations on supercomputers at the Neuroscience Gateway Portal (NSG). For further information, see the https://www.nsgportal.org web page. Dave Beeman