Digging into Julia's package system

The Julia client by default fetches all packages from a package server at https://pkg.juilalang.org, which implements a simple HTTP protocol for serving content-addressed immutable tarballs of package code. These source tarballs are stored persistently in S3 and replicated across a global network of servers that keep them forever. So even if GitHub were to disappear off the face of the earth, every registered package version would continue to be available to install via package servers. So no, Julia cannot get left-padded.