User-Agent headerIn computing, the User-Agent header is an HTTP header intended to identify the user agent responsible for making a given HTTP request. Whereas the character sequence User-Agent comprises the name of the header itself, the header value that a given user agent uses to identify itself is colloquially known as its user agent string. The user agent for the operator of a computer used to access the Web has encoded within the rules that govern its behavior the knowledge of how to negotiate its half of a request-response transaction; the user agent thus plays the role of the client in a client–server system.
Client (computing)In computing, a client is a piece of computer hardware or software that accesses a service made available by a server as part of the client–server model of computer networks. The server is often (but not always) on another computer system, in which case the client accesses the service by way of a network. A client is a computer or a program that, as part of its operation, relies on sending a request to another program or a computer hardware or software that accesses a service made available by a server (which may or may not be located on another computer).
HCL DominoHCL Notes (formerly IBM Notes and Lotus Notes; see Branding below) and HCL Domino (formerly IBM Domino and Lotus Domino) are the client and server, respectively, of a collaborative client-server software platform formerly sold by IBM, now by HCL Technologies. HCL Notes provides business collaboration functions, such as email, calendars, to-do lists, contact management, discussion forums, file sharing, websites, instant messaging, blogs, document libraries, user directories, and custom applications.
Eudora (email client)Eudora juːˈdɔərə is an email client that was used on the classic Mac OS, Mac OS X, and Microsoft Windows operating systems. It also supported several palmtop computing platforms, including Newton and the Palm OS. In 2018, after being years out of print, the software was open-sourced by the Computer History Museum. Eudora was developed in 1988 by Steve Dorner, who worked at the Computer Services Organization of the University of Illinois at Urbana–Champaign.
Apple MailApple Mail (officially known as Mail) is an email client included by Apple Inc. with its operating systems macOS, iOS, iPadOS and watchOS. Apple Mail grew out of NeXTMail, which was originally developed by NeXT as part of its NeXTSTEP operating system, after Apple's acquisition of NeXT in 1997. The current version of Apple Mail utilizes SMTP for message sending, POP3, Exchange and IMAP for message retrieval and S/MIME for end-to-end message encryption.