["Your E-Mail Is Obsolete", Byte, Feb 1997 ].
ACAP grew to encompass several other areas, including bookmark management for web browsers - it's effectively a roaming protocol for Internet applications. ACAP is in use by at least four clients and three servers to varying degrees, but it has never gained the mindshare of Lightweight Directory Access Protocol. It's rumoured to be the most complex Internet Engineering Task Force designed protocol ever, which has caused serious problems for server implementors. It's also markedly similar to Lightweight Directory Access Protocol on some levels, which has caused confusion.
Unlike LDAP, ACAP was designed for frequent writes, disconnected mode access (meaning clients can go offline and then resynchronize later), and so on. It also handles data inheritance, sometimes known as stacking, which provides easy creation of defaults.