CalDAV is a standard protocol (RFC) that enables calendar access via WebDAV.

CardDAV is an address book client/server protocol designed to allow users to access and share contact data on a server.

The CardDAV protocol is being developed by the IETF and and is currently an internet draft.

Microsoft Exchange ActiveSync is a data synchronization protocol patented by Microsoft for synchronization of mobile devices with servers (or PCs).

Global Access List is a directory that contains entries for every user, group and contact within an organization.

Lightweight, hand-held computer, designed for use as a personal organizer with communications capabilities.

Internet Message Access Protocol – a protocol allowing a client to access and manipulate electronic mail messages on a server. It permits manipulation of remote message folders (mailboxes), in a way that is functionally equivalent to local mailboxes.

iCalendar Message-Based Interoperability Protocol specifies a binding from the iCalendar Transport-Independent Interoperability Protocol (iTIP) to Internet email-based transports.

iCalendar Transport-Independent Interoperability Protocol

Lightweight Directory Access Protocol – a protocol for accessing on-line directory services.

Mail API –a programming interface from Microsoft that enables a client application to send to and receive mail from Exchange Server or a Microsoft Mail (MS Mail) messaging system. Microsoft applications such as Outlook, the Exchange client and Microsoft Schedule use MAPI.

Message Digest 5 is a widely used cryptographic hash function with a 128-bit hash value.

Set of data associated with a file, directory or other network resource that defines the permissions that users, groups, processes or devices have for accessing it.

Personal Information Management (Contacts, Calendar, Tasks, etc.)

Simple Mail Transfer Protocol – a protocol defined in STD 10, RFC 821, used to transfer electronic mail between computers, usually over Ethernet. It is a server to server protocol, so other protocols are used to access the messages.

User Datagram Protocol – Internet standard network layer, transport layer and session layer protocols which provide simple but unreliable datagram services.

port number for User Datagram Protocol

vCal is an open source calendar standard for Vision PIM. VCal can export itself to an RSS/RDF/WDP feed or publish itself to the internet using WebDAV and PHP. It can be exported to the iCalendar or vCalendar formats as well. VCal is not to be confused with the more known vCalendar format in that it is a completely different format.

Electronic business card that automates the exchange of personal information typically found on a traditional business card. The vCard is a file that contains the user's basic business or personal data (name, address, phone number, URLs, etc.) in a variety of formats such as text, graphics, video clips, and audio clips.

Web-based Distributed Authoring and Versioning – refers to the set of extensions to the Hypertext Transfer Protocol (HTTP) which allows users to collaboratively edit and manage files on remote World Wide Web servers.