Kate has been part of KDE Software Compilation since release 2.2 in 2001.Because of the KParts technology, it is possible to embed Kate as an editing component in other KDE applications.
The integrated development environment KDevelop, the web development environment Quanta Plus, and the LaTeX front-end Kile are three of the major KDE applications making use of Kate as an editing component.
Kate is a full-featured programmer's editor with syntax highlighting for over 150 filetypes.The syntax highlighting is extendable via XML files and can also specify code folding rules. It has support for search and replace using regular expressions and supports auto-detection of file encodings. Supported encodings include UTF-8, UTF-16, ISO-8859-1 and ASCII.
Kate can be used as a modal text editor by using its vi input mode which emulates the vi editor.
By using sessions, one can customize Kate for different projects. When using sessions, the list of open files, the list of enabled plug-ins and the window configuration are saved, allowing Kate to be customized for a given project.
Kate is really the most complete GUI (Graphical User Interface) text editor I've ever tried. Some of the basic features it has (and practically any good text editor intended for programmers should have) are: good highlighting for various programming languages (it offers default syntax highlighting for an amazing number of source files, like Bash, Perl, C, Lisp, Python, and even Quake scripts are supported), the block selection mode, which allows you to select text based on columns instead of selecting whole lines, indentation which works good enough, export to HTML and even a spell checker.
Being a KDE application, Kate can transparently open and save files over all protocols supported by KIO. This includes HTTP, FTP, SSH, SMB and WebDAV.
Kate is built using the KPart technology and the Kate application is just a graphical shell around the editor component, referred to as katepart. This KPart component is embedded by other KDE programs as well. The Kate application uses the Konsole kpart to get an embedded terminal.
Plugins and scripting.
Kate can be extended through plugins written in C++ and scripts written in QtScript. Functionality implemented as plugins includes file browsers, ctags support and functionality for building software projects and quickly jumping to compilation errors.
Kate can be successfully used for both taking notes, editing configuration files, or creating small projects like a C application or a command line tool.
Kate allows you to save sessions and to work with several files at a time. For example, you can split the view vertically or horizontally, work to a file in one view and another one in the second view. Changes will be visible to both files if they are the same. It also provides an embedded terminal, which can use Konsole's default settings. The terminal is very helpful if you work at a source file and then you want to compile without opening another shell application.
It has a very fast load time, very stable and benefits of a complete configuration options via the Settings -> Configure Kate... menu option.
Kate definitely deserves its name, of an advanced text editor. It offers practically anything you can ask from a text editor, and even more.