The focus of this category is on Internet or Intranet clients that serve two or more purposes in the server-client architecture, particularly the client software.
The Internet consists of servers and clients, and they involve both hardware and software. The machines that provide services to other machines are servers, while the machines that are used to connect to those services are clients, and software is involved in the operation of both servers and clients.
There are web servers, email servers, chat servers, FTP servers, and so on, covering all of the needs of Internet users. When you connect to a website on the Internet, you are a user, and the device you are using to connect to the Internet is a client machine.
To view a webpage, you will generally use a web browser, such as Chrome, Opera, or Safari. In response to the request made by your browser, the server machine finds the page that you are requesting and sends it to you, assuming that you have permission to view it. As a client, by your direction, the browser has a specific purpose, so it directs its request to the specific software server running on the server machine. When you are operating a browser on your device, it will want to talk to the webserver on the server machine, not the telephony or email server.
A server provides several services, which it makes available through numbered ports, one for each service that is available on the server. As an example, when a server machine running both a web server and a file transfer protocol, such as FTP, the webserver would typically be available on port 80, while the FTP server would be available on port 21. Clients connect to a service at the specific IP address and port number the corresponds to the service it is seeking to access.
Once a client has connected to a service on a particular port, the service it accesses is accomplished through a specific protocol, which describes the way in which the server and client will communicate. Although other protocols may also be supported, every web server on the Internet conforms to the hypertext transfer protocol (HTTP).
So, web browsers are clients that connect to web servers to retrieve web pages for display. The Internet is made up of several other types of servers and clients, as well. Email clients retrieve email from mail servers, while chat and instant messaging are accomplished through a variety of clients, which vary according to the protocol being used.
There are several types of clients performing a variety of tasks on the Internet. These include blog client software, email clients, FTP clients, HTTP clients, instant messaging clients, Internet relay chat clients, MUD clients, Usenet clients, and several others, such as clients providing telephony services, video conferencing, and various file-sharing services.
Client software designed primarily for a specific purpose may be listed in a category representing that service, while those that provide two or more services may be listed in this category. In some cases, it may be appropriate for a resource to be listed in more than one category. For example, client software that is designed primarily to provide chat services may be listed in the Messaging & Chat category, but if it also allows files to be shared from one user to another, it might also be listed in this category in recognition of its secondary purpose.
Recommended Resources
Available through the terms of the GNU General Public License, Citadel is a collaboration suite that includes messaging and groupware, featuring email, scheduling, and a calendar, address books, forums, a mailing list server, instant messaging, wiki and blog engines, multiple domain support, RSS aggregation, and a web interface. Originating in 1988, Citadel is descended from the Citadel family of programs that powered a bulletin board system (BBS) in the 1980s. Documentation is provided.
http://www.citadel.org/
Developed by Flock FZ-LLC, Flock is a proprietary messaging and collaboration tool, available for macOS, Windows, Android, iOS, and the web. Flock allows users to configure external applications and integrations from the Flock App Store, and receive notifications and updates directly in Flock. Included is a limited free plan, a monthly or annual subscription plan, and a custom plan for large organizations. Its features include corporate chat functions, video calling, file sharing, and search.
https://flock.com/
Originating in Israel in 1996, ICQ is a cross-platform instant messaging and VOIP client developed by Mirabilis. Acquired by AOL in 1998, it is currently developed by the Mail.Ru Group. ICQ features offline user messaging, multi-user chats, free SMS sending, resumable file transfers, greeting cards, multiplayer video games, and a searchable member directory. User accounts are password-protected, and a facility exists for password recovery. The site is available in English or Russian.
https://icq.com/
Distributed under the terms of the GNU General Public License, Kommuni-K is a complete communication system. Gathering several functions into a single, modularized client/server system, the open-source application includes ICQ-like instant messaging, chatrooms, Napster-like file sharing, bookmark sharing, and a graphical user interface (GUI). It may be freely downloaded from the site, along with the source code. Users may rate and review the program, and report bugs.
https://kommunik.sourceforge.io/
Forked from Zarafa, Kopano offers a variety of features, including email, team chat, video meetings, and organizational tools that include a calendar, contacts, notes, and tasks, as well as resources for storing, sharing, creating, and collaborative editing of documents. Three annual subscription plans are compared side-by-side, showing the features, limitations, and pricing of each. The source code is available, along with support services, and a free trial.
https://kopano.com/
The WhatsApp Messenger is a cross-platform messaging and voice-over-IP (VoIP) service currently owned by Facebook. It allows users to send text and voice messages, make voice and video calls, and share images, documents, user locations, and other data. The application generally runs on mobile devices, but it is also accessible from desktop computers as long as the user’s mobile device remains connected to the Internet while they are using the desktop application.
https://www.whatsapp.com/
