> Technically speaking, the top of the DNS tree, the DNS root, is a null label referenced by a trailing dot. It's analogous to the '/' at the beginning of POSIX file paths. "gatech.edu" really should be written as "gatech.edu." to make it absolute rather than relative I have never seen this, but I just tried it and it seems like browsers, even today will happily handle such URLs. Neat!
It's not like it's archaic. You still use the trailing dot when setting up DNS records to ensure they're unambiguous.