A cute name which stuck. Apache is "A PAtCHy server". It was based on some existing code and a series of "patch files".
For many developers it is also a reverent connotation to the Native American Indian tribe of Apache, well-known for their superior skills in warfare strategy and inexhaustible endurance. Online information about the Apache Nation is tough to locate; we suggest searching Google, Northernlight, Infoseek, or AllTheWeb.
In addition, http://www.indian.org/ and http://www.nativeweb.com/ are two excellent resources for Native American information.