Clementine 0.5: New and Improved KDE4 Port of Amarok 1.4

Clementine is a port to KDE4 of one of the most beloved music players on Linux, Amarok 1.4. The latest release brings several new features, including iPod, MTP and USB mass storage disks support, queue manager, support for Wii Remote to control it, and numerous bug fixes to already existing features.

Clementine 0.5 in Kubuntu 10.10 Maverick Beta

Krita - The KDE Answer to GIMP

I was recently browsing through various Linux news sites and bumped into this article, a taste of a comic done in Krita, the KDE painting and image editor application, which is part of the KOffice suite. Now I rarely use image editors, and I'm totally untalented at it, but when I do, I use GIMP for basic cropping, coloring or other simple stuff. Anyway, I remembered I only tried Krita once, in KDE 3, and I was a little dissatisfied with it (can't remember exactly why), so at the time I decided to stay with GIMP. This is why this article brought Krita again in my attention, so I decided to give it a spin and see how it looks like.

KDocker: Dock Any Application in the System Tray in KDE, GNOME & Xfce

I bet at one point or another you felt you missed the system tray integration feature in some application, be it xterm, an audio player, a file manager or any other program. Well, KDocker is just the thing which comes to help: a simple, yet practical docking application built for KDE4 (older KDE3 version can be found here), but not only. Let me tell you how to use this program in a productive and useful manner.

KDocker 4.3 docking an xterm instance

KDocker is a docking application for KDE4 which allows you to dock any application in the system tray. The great thing about KDocker is that it works not only in KDE, but also in GNOME, Xfce and other window managers which are compliant with the NET WM standard.

The project is hosted on Launchpad, being actively developed, with the latest version (4.4) released earlier this year, on July 17. To install it in Ubuntu, type in a terminal sudo apt-get install kdocker, then launch it by pressing Alt+F2 and typing kdocker in the run dialogue window that appears.

Here's how to use: first, start it, then select the window which you want to dock. Below is a screenshot of xterm docked in the system tray using KDocker:

Here are several options KDocker provides besides only docking applications:
- it allows to skip the taskbar or the pager (so the application is not shown on the taskbar/pager)
- make the window sticky
- iconify when minimized/obscured or focus is lost or on close
- show a balloon when the window title changes

KDocker options

Now, one of the real uses KDocker provides is the ability to run it as a command, e.g. kdocker application_name and eventually create a desktop shortcut to this command, or make it start at the login. For example, creating a desktop shortcut in KDE to automatically start Konsole and put it in the system tray can be done like this:

First, create a file on the desktop (well, on the Desktop Folder widget actually) called anything.desktop (or whatever name you like, but with the .desktop extension). Put the following content in it:

[Desktop Entry]
Exec=kdocker konsole
Icon=konsole
Name=Konsole (Docked)
Type=Application
Comment=Console

Create a .desktop launcher to anything you want to dock

And save the file. Now, you can click that desktop shortcut to launch Konsole in the system tray.


Let's say you want to launch a terminal-based application inside Konsole, which should be docked in the system tray. The example that follows is for Midnight Commander, the powerful file manager with a text user interface:

[Desktop Entry]
Exec=kdocker konsole -e mc
Icon=konsole
Name=Konsole (Docked)
Type=Application
Comment=Console

The -e argument tells Konsole to execute the command mc after starting.

Launching Midnight Commander in Konsole and docking it in the system tray

Have some more uses for KDocker? Please share in the comments below.

How-To: Set Up KMail With GMail and IMAP

According to Wikipedia, IMAP (Internet Message Access Protocol), together with POP is one of the most popular protocols for email retrieval. In this short tutorial I will show you how to set up KMail (the default email client in KDE4 and also most - if not all - distributions which ship it, like Kubuntu) with a GMail account, using IMAP as a protocol.

Here are a few steps easy to follow:

1. Login to the GMail account
After logging in to GMail, click on Settings on the upper-right corner, and then click on the Forwarding and POP/IMAP tab. Tick the Enable IMAP option in the IMAP Access section, and then click the Save Changes button.

2. Fire up KMail
Press Alt+F2 and type kmail in the run box that appears. KMail should start, so if a first-run wizard appears, just close it.

3. Configure KMail to use IMAP settings for your GMail account
In KMail, go to Settings->Configure KMail... and click on the Accounts tab.

In the Receiving tab, click the Add... button on the right and then tick the IMAP option in the pop-up window that appears. Next click OK:


Now, a window with IMAP details should appear. Enter the following data:
Account name: you can leave this to the default value, IMAP Account
Incoming mail server: imap.gmail.com
Port: leave this to the default port 143
Login: your GMail account (e.g. myemail@gmail.com)
Password: your email (GMail) password


Do not close this window for now. Go to the Security tab and select the Use SSL for secure mail download radio button. This will use encryption for transferring your emails. Click OK, then Apply in the main configuration window.



This should be all. This part takes care about incoming emails via your GMail account.

For outgoing email, go again to Settings->Configure KMail... and then click on the Sending tab. Next, click Add..., check the SMTP account type in the window that appears, give it a name and click the Create and Configure button. Fill in the Outgoing mail server field with smtp.gmail.com and then click OK:

Your GMail account is now synchronized and you can now access it directly in KMail

Amarok 2.3.2 Beta 1 Review

Well, well, well, guess who's back! It's been over seven months since i last published an article here at TuxArena, but now we're back on track and kicking! The series of reviews continues today with an article about one of the most popular audio player out there (and why not admit it, even controversial). I'm talking Amarok here.

The version tested is the 2.3.2 Beta 1 release, put out earlier this year, running on top of Kubuntu 10.10 Beta. Amarok improved a lot since I last took a look at it (I'm still using KDE 3.5 with the old - but stable - Debian Lenny).

First of all, let's have a look at the interface:

Amarok 2.3.2 Beta playing

Amarok also provides a so-called Slim Toolbar which arranges the upper side containing the Play/Pause, Next/Previous Track buttons in a more compact way:


Among the good features Amarok comes with:
- Equalizer
- Powerful collection management system (although the playlist is a little buggy)
- Scripts
- Lyrics, Wikipedia, & several more widgets
- Cover manager and fetching system
- Online music sources
- File browser
- Podcasts support
- Bookmarks
- On-Screen Display
- Fadeout feature


Minuses compared to the 1.4 version are lack of statistics, stability (it's less stable and reliable - it's one of the players which at the moment can ruin your listening experience by crashing or making other surprises). I'm sorry to say this as an Amarok fan and promoter, but this is the truth as I see it.

Scanning the collection is very fast in 2.3.2, and I was really impressed to see that in less than four minutes Amarok successfully scanned a collection of almost 9000 audio files (Ogg and FLAC formats only), and populated the playlist in a little over 1 minute with all of them. That's on my Core 2 Duo 1.8 GHz.

The problem with the playlist is that Amarok still has issues with categorizing songs which are part of a compilation by different artists, and this results in a messy playlist. I talked about this probably over one year ago, but it seems it hasn't been fixed not even until today. Also, it fails to correctly fetch album covers which are in the same directory with the songs from an album. This is frustrating and pretty much... amateurish. I mean, it's been over two years now!

The playlist can get messy - Amarok still has issues with organizing albums which are compilations with more than one artist

The configuration window allows to customise general settings, like enabling/disabling the system tray or the OSD, select which web services you want to have listed in the left panel, show moodbar or configuring an external MySQL database for the music collection.

The second time I started Amarok it jumped from a song to another, refusing to play any sound. I had to kill it in Konsole. The output was something like "amarok(2735): couldn't create slave: "Unable to create io-slave:
klauncher said: Unknown protocol ''." I really don't know whether this is Amarok's fault, or Phonon's. This happened after hitting Ctrl+J to jump to the search box and typing an artist in there, then Enter. Amarok refused to play any more songs after this, even after restarting the X Server and logging back in. If someone can help me with that, I'd be truly thankful.

Of course, I have to mention again that this is only a beta, and it was tested in a beta distribution too (I guess by this time we all know about the quality of Kubuntu releases).

Overall, Amarok 2.3.2 has powerful features, and it surely looks like a lot of work has been put in it (well, except for the playlist problems), but thing is, a lot of people still prefer the older 1.4.10 player, which is rock-solid compared to its KDE 4 port.

Pluses:
+ Equalizer with presets
+ collection manager
+ Wikipedia and lyrics widgets

Minuses
- still needs more features
- lack of stability

Kubuntu 9.10 Karmic Koala (Alpha 4) Overview & Screenshots

The fourth alpha of Ubuntu 9.10 was released a few days ago and since I covered it earlier in this article, here I'll briefly overview Kubuntu, the KDE-based distribution of Ubuntu. All the screenshots were taken after a complete dist-upgrade, so the software should be completely up-to-date as of today.


The new Karmic currently comes with Linux kernel 2.6.31, KDE 4.3, Amarok 2.1.1 as the audio player, Dragon Player as the default video player. In one of my previous articles I pointed out some of the new features in KDE 4.3, some of which are implicitly included in Karmic, like the new Plasma look, called Air, or the new KRunner.

Konqueror is a hell of a browser, with countless features and ease of use for those who are already used to it. These are not all, but it comes with web shortcuts, enabled AdBlock filters, profiles, plugins, shortcut to various web page translations, user agent switching and so on. There was a time when Konqueror was very unstable, but now I encountered no crashes, with Flash enabled. On the other hand it was always mature regarding features and usability, since the KDE3 days. YouTube works fine also, but I had to manually install the Flash plugin, although package flashplugin-nonfree was already installed.



Compared to the current stable Kubuntu, this one seems to be more responsive and faster, although resizing windows with desktop effects enabled can still be slow, but I tested this on my older GeForce 7600. Compositing works very well in KDE 4.3, at least that was my experience with it, and all the KDE applications interact good enough, but Firefox or GTK applications for example may be a little choppy (for example when using the Magic Lamp desktop effect). Of course, this is an alpha.


Some windows still have simple size issues, they are either too small or too big and need resizing.

One thing that bothers me at Konsole is that it still doesn't include a right-click context menu to close separate tabs, instead this functionality is available using Ctrl+Shift+W.


For some reason the Save as dialogue in KSnapshot won't show certain files, although their extension is the same selected in the dialogue. I noticed this happens only when saving on partitions mounted manually. This seems to happen at random.

Amarok 2.1.1

Since this is an alpha, there are still bugs and most of them come in applications which are not included in KDE, for example in Amarok 2. Also, the sound system doesn't seem to work, although this is a KDE problem I think, because on Ubuntu it does work.

Overall, this looks promising. The developers will have enough time to polish it until October, and KDE 4.3 really behaves very nice, not to mention the look.

How-To: Install KDE 4.3 in Ubuntu/Kubuntu 9.04 Jaunty Jackalope

KDE 4.3 was released just yesterday, and it comes with a lot of great new features and improvements, like the the new Plasma theme called Air, new Plasma widgets, several improvements to Dolphin, the default KDE4 file manager, improvements to the KDE games, and these are just a tiny part of all the improvements KDE4 introduced. The full announcement including reader's changelog can be found on the official KDE4 website, here.

Kubuntu comes with an older release of KDE4, but there is a PPA (Personal Package Archives) available which includes the newest packages for Jaunty, so in order to install it just follow the steps below.

First, open up a terminal like Konsole or GNOME Terminal and edit the sources.list file using your favourite text editor, e.g.:

sudo nano /etc/apt/sources.list

Or, for Kate:

sudo kdesu /etc/apt/sources.list

If you are installing KDE from Ubuntu, you can use Gedit:

sudo gedit /etc/apt/sources.list

Enter your user password and add the following repository line:

deb http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu jaunty main

Next, make sure to save the file (Ctrl+O followed by Ctrl+X in Nano) and update the package lists:

sudo apt-get update

All you have to do now is to install the new KDE 4.3 environment by issuing:

sudo apt-get dist-upgrade

Should take a while. This will fetch and install all the newer packages from the freshly added repository. To see the new KDE 4.3 installation log out and log back in KDE, or open up Konsole and type:

sudo /etc/init.d/kdm restart

KDE 4.3 RC2 Released

The KDE project put out the second release candidate of the upcoming KDE 4.3 on July 9th. This comes only a few days after the first RC was available. This release is codenamed 'Canteras' and it is specifically intended for testing purposes and bug reports only.

KDE 4.3 will include many Plasma improvements, several changes, PolicyKit integration, Geolocation services and many bug fixes.

According to the official announcement, KDE 4.3 is expected at the end of July.

Review: Gwenview 2.3 - The Powerful KDE4 Image Viewer

What is Gwenview?
I'm sure most of (if not all) KDE users are familiar with Gwenview, especially since it became the default image viewer in KDE4. Gwenview is not only a powerful viewer for images, but also a basic image manipulation application, and with version 2.3 it allows even video previews. Although video support was available in 1.4 (which was for KDE3), it was missing in the KDE4 port of Gwenview, but with this new release shipping with the upcoming KDE 4.3, this feature is back.

Gwenview 2.3 in Kubuntu 9.04 Jaunty Jackalope

Overview
Gwenview supports practically any image format handled by Qt, like PNG, JPG, BMP, XPM, TGA or PNM. These are not all though, and even the SVG (scalable vector graphics) format is supported.

Basically, Gwenview has two modes: browser view and image view (which can also be viewed in fullscreen mode). The browser mode displays previews of images in the current directory as thumbnails which can be resized, while in view mode a single image is displayed and it occupies most of the window space. The left sidebar in view mode can be shown or hidden using F11 and includes three tabs:
- Folders, which is the file browser, displaying directories in tree view mode
- Information, which shows image info, allows to set tags and ratings
- Operations, which can show the KDE file properties window, or actions like copy to/move to and delete current image

Browse mode, without the left sidebar

In browse mode, Gwenview displays thumbnail previews of images in the current directory, and upon moving the mouse cursor over an image, four options appear above it, allowing to delete, view image in fullscreen or rotate it left/right.

Thumbnail information can include filename, modification date and current rating, and the thumbnails can be sorted by name, date and size.

The cool thing about Gwenview is that it allows the user to set tags and ratings for each image individually, and it will also display a rich window containing information about the currently selected image. Viewing images as a slideshow is also available.

Left sidebar shows info, ratings and tags, but it also includes a file browser

Among the actions which Gwenview allows to perform without the need of plugins are red eye reduction, rotate image, resize, crop, flip, all those available in the Edit menu.

When performing actions like rotating or mirroring an image Gwenview will ask whether to save it or not, in a nice, unobtrusive fashion:

Asking to save modified file(s)

When in fullscreen mode, Gwenview will display a utilities bar at the top (which can be hidden automatically), showing images in the current directory as thumbnails, access to functions like rotate image, and even a fullscreen configuration window, allowing you to customise the slideshow mode (loop, interval). See below:

Fullscreen mode

What's new in 2.3
Except for video previews, another new feature in 2.3 is the improved history feature. The history will not only show recently accessed folders, but it also includes an 'url bag' or recent URLs place, where all the links to images go, including the ones from Kopete or Konqueror. So if somebody sent you a link in Kopete which you opened directly with Gwenview, you don't have to search for it in the chat history afterwards, Gwenview will display it under the recent URLs section.

My personal opinion is that an image viewer should only be an image viewer (and eventually an image editor) and the reason for it is that video previews seem to slow down things, especially when you need to view some images and have to wait for some video to load. Anyway, I'm sure there are people who like this feature a lot, and it seems to work flawlessly in Gwenview. It almost gave me an impression that I'm using a video player, not an image viewer! See for yourself:

Videos with Gwenview

General behaviour
I noticed that changing the image size from the bottom size bar in view mode is done extremely fast even for high resolution images. Although this doesn't apply to SVG, JPG and PNG resizing was done pretty fast. Gwenview seems pretty stable, I had no crashes and no misbehaviours while testing it. Instead, Gwenview crashed when trying to use the Plugins -> Import -> Scan Images plugin and hitting Cancel at the Looking for devices. Please wait. window. However, not hitting Cancel will open the scan dialogue, and although I have no scanner, Gwenview successfully captured and saved images from my TV-Tunner.


Plugins
Gwenview also comes with plugin support, but you'll have to install the kipi-plugins package in order to be able to use them. To list several plugins available (but not all):
- print images
- convert to black and white
- email images
- edit meta data
- scan images


Configuration
The configuration window currently includes basic options, like background colour when viewing images and image thumbnails, transparent background, mouse wheel behaviour or the orientation of the thumbnail bar. As any KDE application, Gwenview allows to configure its shortcuts and set global shortcuts if needed too.

Documentation
Although not very comprehensive, Gwenview currently includes a Handbook (F1 keyboard shortcut or from the Help menu) and some useful information can be found on the official website too. See this blog for Gwenview updates too.

Conclusion
Gwenview is complete. The impression Gwenview left me is that of an awesome application. It takes browsing and managing images to a new dimension and it makes it a real pleasure. It has more than enough features for an image viewer, and it is incomparable better than the 1.4 series. For a KDE4 user, I couldn't think of another viewer which can do what Gwenview does, and still keep a clean, organized, and customisable interface.
Official homepage

KDE 4.3 RC1 in Kubuntu 9.04 - Overview & Screenshots

I took some time today to install and take for a spin the latest version of KDE4 today, release 4.3 RC1. I installed the packages from the Kubuntu backports repositories, as explained in this tutorial. All the screenshots were taken at 1280x1024 and desktop effects enabled.

The first change it jumps into the eye is the new Plasma appearance, called Air now. It is brighter than the old one, but I found it looking not so appealing, at least not for the desktop widgets. Here's how the desktop looks in Kubuntu Jaunty, with several widgets running on the desktop:

New look for Plasma

Dolphin, the default file manager

KRunner received several great improvements: it now displays the applications to be run as a list (see screenshot) and this list can be customised too. See below:

According to the announcement on the KDE official website, this release got many Plasma improvements, several game updates, PolicyKit integration, and several other changes or improvements.

For those who like desktop effects a lot and have a video card capable of supporting OpenGL, a combination of wobbly windows + window transparency and the magic lamp minimize effect should be very satisfying.

Konsole

I noticed plasma-desktop eats constantly 30% CPU (Core 2 Duo 1.8GHz, 1 GB DDRAM2 and nVIDIA 7600GS), which is a lot greater than in KDE 4.2 which comes by default with Kubuntu. Still, this is just a release candidate, and the upgrade was performed over an existing KDE installation using dist-upgrade in Kubuntu.

Konqueror in 4.3RC1 - KDE web browser

System Settings

Okular, the default document viewer in KDE4

Gwenview is now included in the KDE distribution

How-To: Install KDE 4.3 RC1 in Kubuntu 9.04 Jaunty Jackalope

The first release candidate of KDE 4.3, the next major version of KDE4, was put out on July 1st and comes with new features and a lot of Plasma improvements and bug fixes.

In this short tutorial I'll show you how to install KDE 4.3 in your Kubuntu 9.04 machine with the help of the Kubuntu Backports PPA (Personal Packages Archive) repositories. Just follow the steps below:

1. Edit your /etc/apt/sources.list file with root privileges using your favourite text editor:

E.g.:
- for nano:

sudo nano /etc/apt/sources.list

- for Kate

kdesudo kate /etc/apt/sources.list

And add the following line:

deb http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu jaunty main

Make sure to save the file and proceed to the next step.

2. Update your sources lists
Type, using your user password:

sudo apt-get update

If you haven't added the trusted key of this PPA, don't worry about the warning, and type 'y' when it asks to continue the installation at the next step.

3. Install KDE 4.3

sudo apt-get dist-upgrade

If you don't have KDE installed and want to try this RC, then type:

sudo apt-get install kde

Or, better yet:

sudo apt-get install kde-core plasma

To get only the core KDE packages.

Notice that this command will replace your existing KDE 4.2.2 installation with the latest KDE found in the repositories. According to the Kubuntu website, X may die during the upgrade, but the upgrade will be performed, so just restart the computer after upgrading.

KDE 4.3 Release Candidate (RC) 1 Out

The KDE project put out today (July 1, 2009) the first release candidate of the upcoming version of KDE4 desktop, 4.3. According to the announcement on the official website, the highlights of this release are:

- a new tree mode in System Settings
- integration of technologies like PolicyKit (an application for controlling privileges) or Geolocation services
- crash dialogue UI remake
- many Plasma improvements
- Plasma add-ons
- several additions to the kdegames package
- many bug fixes and other improvements

Coming up soon a tutorial for installing this release candidate on Kubuntu 9.04.

Update: Here is the tutorial.

Top 10 KDE4 Applications

Yakuake - Great terminal application
Yakuake is a very popular Quake-style terminal application which sits in the background unless it's invoked with the (default) F12 global shortcut. It can inherit Konsole's settings and it is probably the best alternative to Konsole. Just like Konsole, Yakuake supports full transparency effects, various colour schemes and backgrounds, middle-click paste and tabs. Definitely an essential tool.
Homepage

Yakuake

Amarok 2 - Probably the most popular Linux audio player (full review here)
Amarok's port to KDE4 was probably one of the most controversial releases in the last few months and it generated many discussions whether Amarok 2 took the right way. My answer: yes. Although Amarok 2 was initially stripped by major features (to mention a few: lack of equalizer, currently poor functionality), but instead it is a new ground for new features. It's true, Amarok 2.0.2 was effectively full of bugs (I'm sure not even the devs can argue against this), but the upcoming 2.1 release includes a new, customisable playlist which should please users which complained about it. Amarok 2 still misses a lot of features, but the good thing is that developers are aware of the needs of users and plan to implement them in future versions. Among the new features this wonderful player comes with are widget support, a completely rebranded playlist and interface (if you ask me, I like how the space is managed in the interface), support for many services like Last.fm, Magnatune, and several other music stores. Development advances at a fast pace and pretty soon I'm sure Amarok 2 will be what Amarok 1.4 was and even more.
Homepage

Amarok 2.0.2

K3b - Arguably the best KDE burning application (full review here)
Even if it is currently in alpha, K3b has a port for KDE4 now. No new features available and the interface hasn't changed, but this is the ground for what is to come next. K3b is probably the most powerful and full-featured, open-source CD/DVD burning application on Linux.
Homepage

K3b 1.65.0 alpha - first KDE4 port

SMPlayer - Full-featured video player using Qt
Now that VLC comes with a Qt interface too, I guess this puts SMPlayer and VLC at the same level, but I opted for SMPlayer because I believe it has a more compact interface and it seems to me to be easier to use.

Although SMPlayer does not actually depend on KDE4 libraries, it's still a Qt 4 application, and one of the most powerful video players out there. Using the mplayer engine, SMPlayer is a very powerful, feature-rich and highly configurable video player, which can play any format around, including DVD ISO images or Matroska MKV videos. One of the great features SMPlayer has for a long time now is the ability to remember all the settings for a specific file (like the time position, video settings, window size and position etc). Very useful when you have to close the player, and then later you have to restart a certain video without the need to scroll to the last position in the video. SMPlayer has an interface which fits well with KDE4 and it allows to configure the shortcuts, it provides icon themes, subtitles support, video functions like rotate video, aspect ratio, or various filters.
Homepage

SMPlayer

digiKam - Photo management application
digiKam is a popular photo management application which constitutes the perfect alternative to the closed-source application from Google, Picasa. Starting with version 0.10 it also has a KDE4 port too. digiKam organises your pictures and photographs into albums and collections and comes with a huge number of options and support for many digital cameras.
Homepage

digiKam 0.10

Krusader - Powerful file manager
With a funny codename, Krusader 2.0 'Mars Pathfinder' was released on April 11 and it is the first Krusader version for KDE4. Krusader was always the first alternative to Konqueror back in the KDE3 days, and its twin-panel interface and powerful features can please any user looking for an advanced file manager for KDE4.
Homepage

Krusader

KTorrent - Full-featured BitTorrent client (full review here)
A while ago I put up a full review of KTorrent for KDE4 here. KTorrent has come a long way and is a completely full-featured BitTorrent client, including various useful plugins, torrent information, rich configuration settings, ability to download only certain files in torrents, possibility to create your own torrents and much more. If you are a KDE user and you didn't give it a try, you surely need to.
Homepage

KTorrent

Gwenview - image viewer and editor
Gwenview is in a continuous development, with more features and improvements added with every new release. Plans for the upcoming 2.3 release of Gwenview include a redesigned places and history handling, which will now include an 'URL bag' (or 'recent URLs' as it will probably be called), so that whenever you start Gwenview to view an image on the web it will keep the address in the history for fast access afterwards.

Gwenview supports various image formats, has good KDE integration, it comes with a file browser and thumbnail previews. One of the features of Gwenview is the ability to use basic image manipulation plugins, which extend its functionality too.
Homepage

Gwenview

Kdenlive - wonderful video editor
Linux has several popular video editors praised by some and hailed by others, and those include Kino and Cinelerra. A newer alternative to those is Kdenlive, which in my opinion is just the perfect application for non-linear video editing in KDE. Kdenlive supports various video formats, includes video and audio effects, and it organises your work in projects. You can create, crop, delete and bassically manipulate videos easily in any way possible with the help of this application.
Homepage

Kdenlive

SpeedCrunch - complex calculator
Maybe not an application which can compete with a video player or image management application, a calculator is still an essential tool for any desktop. SpeedCrunch is a complex calculator application built in Qt 4 and which also features a scientific mode.
Homepage

SpeedCrunch

As you can see, I decided not to include applications which come by default with KDE, so you won't find applications like Kopete or Konsole here. Instead, this is a top of KDE4 applications which I consider most powerful and (probably) essential for any KDE4 user after installing a KDE-based distribution.

Noteworthy applications left out
Unfortunately I couldn't include several good programs either because they are currently in alpha state (due to porting to KDE4 libs) or they don't have a KDE4 version. Included here is Kaffeine, a Xine-based video player which is among the top KDE players, BasKet, an extremely nice notes-taking application and not only: BasKet comes with great features which allow you to build entire projects, not only take notes. KDevelop currently has a beta release of the KDE4 port too, and it is a powerful integrated development environment which allows to program KDE applications. To say nothing about KOffice, for which the first release candidate of version 2.0 was put out just last month. A powerful music editor for Linux is Rosegarden, which is a good KDE replacement for Audacity for example.

Updated: May 3, 2009