An overview of GNOME system services.
Mail & Calendar#
With Evolution Data Server, GNOME provides a single address book and calendar that all applications can use to store and retrieve information. Using Evolution Data Server means that users no longer have to maintain separate lists of contacts in each application, or manually copy events to their calendar.
Applications can also use Evolution Data Server to store and retrieve appointments on the user’s calendar. For example, the clock on the panel shows a simple calendar when clicked. If the user has any appointments scheduled, they are shown alongside the calendar. This makes it easy to see upcoming appointments without opening a full calendar application.
People use computers increasingly to interact with their friends and colleagues. Applications such as email programs, instant messengers, and telephony and video conferencing applications are used to communicate with others. These applications often provide contact lists to help users. Folks takes care of aggregating all these forms of contacts so that you can get all the accounts that belong to one person. This lets software present lists of people in a more useful fashion, instead of showing duplicated people whenever they have more than one account associated to them.
Tracker is a collection of tools that allows you to index files in a user’s system, extracting their content and metadata, and building a database that you can access through the SPARQL query language.
Secrets & Passwords#
Libsecret is a library for storing and retrieving passwords and other secrets. It communicates with the GNOME keyring using D-Bus.
The NetworkManager daemon attempts to make networking configuration and operation as painless and automatic as possible by managing the primary network connection and other network interfaces, like Ethernet, Wi-Fi, and Mobile Broadband devices. NetworkManager will connect any network device when a connection for that device becomes available, unless that behavior is disabled. Information about networking is exported via a D-Bus interface to any interested application, providing a rich API with which to inspect and control network settings and operation.
ModemManager is a DBus-activated daemon which controls mobile broadband (2G/3G/4G) devices and connections. Whether built-in devices, USB dongles, bluetooth-paired telephones, or professional RS232/USB devices with external power supplies, ModemManager is able to prepare and configure the modems and setup connections with them.
UPower is an abstraction for enumerating power devices, listening to device events and querying history and statistics. Any application or service on the system can access the org.freedesktop.UPower service via the system message bus. Some operations (such as suspending the system) are restricted using polkit.
Portals are interfaces that allow sandboxed applications to safely communicate to the system outside the sandbox.
PipeWire provides a low-latency, graph based processing engine on top of audio and video devices that can be used to support the use cases currently handled by both pulseaudio and JACK. PipeWire was designed with a powerful security model that makes interacting with audio and video devices from containerized applications easy, with supporting Flatpak applications being the primary goal.
Media Playback Remote Interface (MPRIS)#
The Media Player Remote Interfacing Specification is a standard D-Bus interface which aims to provide a common programmatic API for controlling media players.
It provides a mechanism for discovery, querying and basic playback control of compliant media players, as well as a tracklist interface which is used to add context to the active media item.