KDE regularly polls as the most popular desktop environment for Linux. However, because more desktops use GNOME applications, to many users KDE might as well be a separate operating system. That is unfortunate, because some of the most feature-rich free applications are designed for KDE.
I am not referring here to utilities like the Kate text editor, the Konsole terminal, or even the Dolphin file manager. All of these are well-integrated into KDE and have all the features any user could want, but most of them are matched by GNOME counterparts. Rather, I am thinking of applications that are outstanding by any measure, the best of breed in their software categories.
For example, here are seven KDE applications guaranteed to ease anybody's work-flow. They are listed alphabetically:
Free software has no shortage of music players. What makes Amarok unique is that it is intended to recreate online the experience of owning a CD or vinyl record. In the middle of its window is a context pane that fetches information about the current song from Wikipedia, as well as lyrics, and current tour information about the performers. A separate utility stores album covers, and plugins enable various online stores, podcasts, and radio stations. You can simply use it to play music, but the context and flexibility makes Amarok the music player of choice for those who view music as more than aural wallpaper and as a central part of their lives.
Originally a camera manager, digiKam has steadily added features over the years. Today, it is a mid-level image editor, complete with tools to crop and scale images and to edit colors, including eliminating red-eye in portraits. It even includes a selection of filters.
Other tools include a batch editor, a light table, and menus for uploading or downloading images from social media sites. Krita no doubt includes more editing options, but as an all-in-one solution, digiKam has a convenience that is hard to beat.
K3B began as a CD burner. However, it long ago morphed into an application for everything connected with optical drives. Yet by choosing intelligent defaults, it manages to avoid causing selection anxiety in uses and remains easy to use. You may not need more than one way to burn a DVD, but when you do, K3B can succeed where simpler applications like Brasero fail.
Besides burning, K3B also has some of the best tools for ripping tracks, including bulk-naming fields.
Klipper has been KDE's clipboard manager for over a decade. What makes it outstanding is that it is installed by default and stores as many entries as you choose. Entries can be edited in the clipboard, as well. For those who regularly edit, it is invaluable, especially for long documents. Why other desktop environments don't have a similar tool by default is a mystery to me.
Krita is KDE's answer to Corel Painter. Originally part of KOffice and now part of Calligra Suite, Krita blossomed when its developers started consulting professional artists about its development.
Krita is best known for its configurable brushes that mimic both different media such as pencils and air brushes, but also different conditions such as the thickness and angle of the brush strokes. Recently, it has started adding animation tools, although the animation feature set is still far from complete.
Krita is comparable to GIMP, but its emphasis is on-line drawing and painting rather than image editing. Making a transition from GIMP can be challenging at first, but, once you grasp its logic, it is easier and more efficient to use.
If you have ever worried about Google Maps storing information about your geographical searches, then Marble is the answer. Running from your own desktop, Marble uses OpenStreetMap to provide an equivalent service to Google Maps, down to using postal codes for searches for both addresses and routes.
However, geographical searches are only part of Marble. Defaulting to a globe, Marble also provides globes and flat maps for countries, precipitation, and temperatures. Other views are based on historical maps, the night sky, and even the moon with detailed legends showing city size, terrain, and places of interest. It currently has an Android port in beta.
In the past, KDE has had so much trouble with file searching that baloo, its present tool, is not even installed on some distributions. However, Recoll is a more than adequate substitute.
Once your home directory is indexed, Recoll searches plain text, email, html, and open document format files, returning hits in a matter of seconds. Better yet, unlike the search tools in the default Dolphin file manager, Recoll is simple enough that you can start using it just by studying it for a few seconds.
You may want to reindex Recoll a couple of times a month so that its results are up to date. Otherwise, I have yet to find a better search tool for any desktop.
As you explore these applications, you might notice that they share a similar design philosophy. Unlike most GNOME applications, they are not aimed at beginners, but at users at every stage. Although you can start using them reasonably quickly, these KDE applications seem to cram every feature that could be possibly relevant into their windows.
If you are accustomed to GNOME applications, this approach might seem like overkill. However, these applications are so complete that several have had no major upgrades for over a year -- there is simply nothing left to add. You may go for months without using some of their advanced features. The more professional your work or aspirations, though, the more likely that sooner or later you will need an advanced feature and be glad to find it waiting for you.