Apache Reference: mod_userdir
mod_userdir - URL Selection by User Names
Since Apache 1.0, src/modules/standard/mod_userdir.c
Rob McCool, Alexei Kosut, Ken Coar (1995)
mod_userdir is a module specialized in mapping (C~username>) URLs to the home pages of the corresponding users; these home pages are usually found inside the home directory of the user or under one or more dedicated home page areas.
Directive:
UserDir