Python has become the defacto standard tool for many people to write tools, command scripts, smaller applications and even large applications. On Windows, it is fairly easy to build application bundles using e.g. py2exe, but on Unix, the situation is less obvious, unless you want to rely on OS specific Python distributions, which often require severall 100MB with of installation on the system and are usually customized in distribution specific ways. Instead of relying on OS installed Python distributions on Unix, our open-source eGenix PyRun provides a more or less complete Python runtime (interpreter and stdlib modules) in a single file, which can be ""installed"" by simply copying the binary to the destination system. The file can be as small as 4.8MB for Python 3.7, by using compressors such as upx. Due to its size, it's also the perfect Python distribution for Docker containers. The talk will show how PyRun works, is built, how to customize it to include additional modules and applications.