Hardware virtualization led to the proliferation of virtual machines in data centers. Greg Kalinsky, EVP and CIO of Geico, in his keynote address to the IBM Think 2019 conference, mentioned the use of 70,000 virtual machines. The management of virtual machines required a different set of tools. In this area, VMware was very successful in the Intel market, whereas IBM's usage of the Hardware Management Console (HMC) was prolific in POWER for creating Logical Partitions (LPARs), or the PowerVM. Hardware virtualization had its own overheads, and it has been very popular for running multiple operating systems machines on the same physical machine.

Multiple monolithic applications have different OS requirements and languages, and it was possible to run the runtime on the same hardware but using multiple virtual machines. During this period of hardware virtualization, work on enterprise applications using the Service-Oriented Architecture (SOA) and the Enterprise Service Bus (ESB) started to evolve, which led to large monolithic applications.