We as rubyists tend to write software that runs on the web, without a deep understanding of what it would take to write the plumbing for that same software. I think it's useful to have a basic understanding of how some of the lower level components of a system work.
I'll discuss the basics of systems programming, using Ruby. I'll talk about syscalls and kernel space vs user space. I'll cover a bit about file descriptors and what they're for. And I'll walk through a small example of a working webserver using those primitive syscalls.