Pere Ubu (Pa Ubu) is the protagonist of several of French writer Alfred Jarry’s more absurdist plays. Ubu is a violent buffoon who is sometimes the King of Poland, sometimes a galley slave and always engaged in some scheme. On his enormous belly is a spiral, his umbilicus.
Here’s the logo of the popular Free Software distro Debian:
Yes, it’s an umbilicus.
There’s a very popular derivative of Debian called Ubuntu, which is allegedly named after a Bantu word. But given the density of wordplay in the Ubu plays we see that Ubuntu is actually a corruption of Ubu en tu, “Ubu in you”. Which reminds us of “Intel inside”, and given that the umbilicus-branded Debian is included, it is literally true. And probably rude.