KFileMetaData provides a simple library for extracting the text and metadata from a number of different files. This library is typically used by file indexers to retrieve the metadata. This library can also be used by applications to write metadata.

Attica is a Qt library that implements the Open Collaboration Services API version 1.6.

It grants easy access to the services such as querying information about persons and contents. The library is used in KNewStuff3 as content provider. In order to integrate with KDE's Plasma Desktop, a platform plugin exists in kdebase.

The REST API is defined here: http://freedesktop.org/wiki/Specifications/open-collaboration-services/

A library for rendering SVG-based themes with stylesheet re-coloring and on-disk caching.

KDED stands for KDE Daemon. KDED runs in the background and performs a number of small tasks. Some of these tasks are built in, others are started on demand.

Framework Integration is a set of plugins responsible for better integration of Qt applications when running on a KDE Plasma workspace.

KBookmarks lets you access and manipulate bookmarks stored using the XBEL format.

Baloo provides file searching and indexing. It does so by maintaining an index of the contents of your files.

This framework implements a lot of file management functions. It supports accessing files locally as well as via HTTP and FTP out of the box and can be extended by plugins to support other protocols as well. There is a variety of plugins available, e.g. to support access via SSH. The framework can also be used to bridge a native protocol to a file-based interface. This makes the data accessible in all applications using the KDE file dialog or any other KIO enabled infrastructure.

KItemModels provides the following models:

1. KBreadcrumbSelectionModel - Selects the parents of selected items to create breadcrumbs.

2. KCheckableProxyModel - Adds a checkable capability to a source model.

3. KConcatenateRowsProxyModel - Concatenates rows from multiple source models.

4. KDescendantsProxyModel - Proxy Model for restructuring a Tree into a list.

5. KExtraColumnsProxyModel - Adds columns after existing columns.

6. KLinkItemSelectionModel - Share a selection in multiple views which do not have the same source model.

7. KModelIndexProxyMapper - Mapping of indexes and selections through proxy models.

8. KRearrangeColumnsProxyModel - Can reorder and hide columns from the source model.

9. KRecursiveFilterProxyModel - Recursive filtering of models.

10. KSelectionProxyModel - A Proxy Model which presents a subset of its source model to observers

KActivities provides the infrastructure needed to manage a user's activities, allowing them to switch between tasks, and for applications to update their state to match the user's current activity. This includes a daemon, a library for interacting with that daemon, and plugins for integration with other frameworks.

KDESU provides functionality for building GUI front ends for (password asking) console mode programs. kdesu and kdessh use it to interface with su and ssh respectively.

Kirigami is a set of high level QtQuick components looking and feeling well on both mobile and desktop devices. They ease the creation of applications that follow the Kirigami Human Interface Guidelines.

ThreadWeaver is a helper for multithreaded programming. It uses a job-based interface to queue tasks and execute them in an efficient way.

Add-on library to Qt which adds JavaScript scripting support.

This library provides access to and handling of calendar data. It supports the standard formats iCalendar and vCalendar and the group scheduling standard iTIP.

A calendar contains information like incidences (events, to-dos, journals), alarms, time zones, and other useful information. This API provides access to that calendar information via well known calendar formats iCalendar (or iCal) and the older vCalendar.

As the names suggest they implement a Client respectively a Server API for the Wayland protocol. The API is Qt-styled removing the needs to interact with a for a Qt developer uncomfortable low-level C-API. For example the callback mechanism from the Wayland API is replaced by signals, data types are adjusted to be what a Qt developer expects - two arguments of int are represented by a QPoint or a QSize.

The KNewStuff library implements collaborative data sharing for applications. It uses libattica to support the Open Collaboration Services specification.

KAuth provides a convenient, system-integrated way to offload actions that need to be performed as a privileged user to small set of helper utilities.

KIdleTime is a singleton reporting information on idle time. It is useful not only for finding out about the current idle time of the PC, but also for getting notified upon idle time events, such as custom timeouts, or user activity.

The Package framework lets the user install and load packages of non binary content such as scripted extensions or graphic assets, as if they were traditional plugins.

KNotifyConfig provides a configuration dialog for desktop notifications which can be embedded in your application.

KPlotWidget is a QWidget-derived class that provides a virtual base class for easy data-plotting. The idea behind KPlotWidget is that you only have to specify information in "data units", the natural units of the data being plotted. KPlotWidget automatically converts everything to screen pixel units.

The Qt Cryptographic Architecture (QCA) provides a straightforward and cross-platform API for a range of cryptographic features, including SSL/TLS, X.509 certificates, SASL, OpenPGP, S/MIME CMS, and smart cards.

The Quick Charts module provides a set of charts that can be used from QtQuick applications for both simple display of data as well as continuous display of high-volume data.