Konqueror is the integrated file manager and web browser that comes as part of the KDE desktop environment. Konqueror was added to KDE at version 2.0, replacing the older kfm. Konqueror is a versatile program and is meant to show off the flexibility of the technologies underlying KDE.
At its heart, Konqueror is a program which connects sources of data with viewers and editors of data. Sources of data are called ioslaves, and they usually correspond to a network protocol or a method of disk access; for example the http: ioslave accesses resources on a World Wide Web server and the file: ioslave accesses resources on a local filesystem. The content of the resource then determines how it is displayed in the Konqueror window. Using the MIME type of the file (since the object in question is usually some kind of file), Konqueror chooses a software component, called a KPart, to take over the main Konqueror window and display the file. Sometimes, as with a text editor component, you are allowed to edit the file, and other times, as with an image viewer component, you are not.
Konqueror's sidebar provides a number of services, including bookmarks, local directory trees, and a history of all non-local addresses visited. It can also hold an embedded media player, a browsable list of available storage devices, and a list of the more unusual 'service' ioslaves that are available.
Konqueror the Web Browser
Konqueror's web-browsing ability is provided by the http: ioslave and a KPart containing the KHTML rendering engine. KHTML's compatibility and standards compliance is just slightly below that of Mozilla, especially following its development at the hands of Apple's Safari team, who have based their browser upon KHTML.
Konqueror's web browser mode provides the usual amenities expected in a modern browser. Tab browsing, password management, pop-up blocking, and a versatile history feature are available. KDE 3.2 includes support for pervasive mouse gestures through KHotKeys and Konqueror is of course included. KDE 3.3 added a built-in search bar, and the so-called Enhanced Browsing feature permits searches to be run from the address bar with special prefixes. For example, to search Google for 'fuzzy peaches', you would type 'gg:fuzzy peaches' into the address bar.
Konqueror the File Manager
But it's the file manager form of Konqueror that is the truly interesting part. File management is normally done using the file: ioslave, but this is not an inherent quality. You can use the ftp: ioslave, for example, and the very same file manager KPart will be used with as many capabilities as the FTP server will allow it to have.
The file management KPart itself has many useful features. In addition to the expected icon and list modes, it includes a Mac OS-style tree view, which behaves like a list mode except that folders can be opened and closed in place and the file manager will display them as a 'tree'. The usual operations are all available: copy, move, make links, delete, etc. The context menu in Konqueror 3.2 also includes 'Copy To' and 'Move To' menu items that allow you to navigate the filesystem with menus and choose a destination in that manner, rather than through the main filesystem view or the sidebar.
It is the variety of available ioslaves that makes Konqueror such a powerhouse, though. The audiocd: ioslave allows audio CDs to be viewed as a 'filesystem' containing WAV, MP3, and Ogg Vorbis files of the contents of that CD, which are then transparently ripped and encoded when copied off the CD. The fish: ioslave is a remarkable achievement; it provides a full filesystem interface to a remote computer through a simple SSH link, requiring only standard Unix utilities or Perl on the other end. The smb: ioslave allows browsing of Windows shares, and the tar: and zip: ioslaves allow browsing within archive files.
Konqueror's file manager mode offers two options for displaying multiple views in the same window. The first, older option is to split the display into multiple independent panes, each of which contains its own KPart. In recent versions of Konqueror, it has also been possible to have a tabbed file manager view with different documents in different tabs. In addition to this, it is possible to have a pane at the bottom of the window with a Konsole terminal emulator for manipulating files with command-line tools. The shell in the terminal follows the directory in the main file manager view.
Konqueror is one of a new breed of file managers, one that ignores, as much as possible, the distinction between local resources and remote resources. The contemporaneous GNOME file manager Nautilus takes much the same view. Although Konqueror's interface is (still) a little overly complicated, work is ongoing to streamline it further to make it easier to learn. The disjunction between the file manager and web browser modes of Konqueror is widening over time, though, and occasionaly some people wonder why they're still one application. Still, the disjunction is less than that experienced with Windows Explorer and Internet Explorer, which though nominally integrated feel like different applications. A large part of the success of KDE is due to Konqueror and its future looks bright.
This writeup is copyright 2004 D.G. Roberge and is released under the Creative Commons Attribution-NonCommercial-ShareAlike licence. Details can be found at http://creativecommons.org/licenses/by-nc-sa/2.0/ .