PackageCompiler is a Julia package with three main purposes:
Creating custom sysimages for reduced latency when working locally with packages that has a high startup time.
Creating "apps" which are a bundle of files including an executable that can be sent and run on other machines without Julia being installed on that machine.
Creating a relocatable C library bundle form of Julia code.
For installation and usage instructions, see the documentation.
Upgrading from PackageCompiler 1.0
PackageCompiler 2.0 comes with a few breaking changes. Read the upgrade guide here for instructions on how to upgrade to version 2.0.