Understand takes about 200-300MB of installation space, depending on which OS it is installed on and will run on Windows (Windows 7 and later), Linux 64bit (CentOS & RHEL 7.4, Ubuntu 16.04, and later) and Mac OSX (Sierra 10.12 and later). For larger code bases the more RAM the better. We recommend 1GB / Million lines of code, it will run on less, but it is much slower.
Use the older builds of Understand if you need a version to run on an older machine.