KDE is not only a desktop environment but also a software ecosystem, providing not only software for regular desktop use, but also tools to create such software. Whether developing for KDE or programming in general or doing even web development, KDE offers programs that can help make any programmer's, or even non-programmer's, life easier and more productive.
Software Programming
KDevelop
A powerful and flexible Integrated Development Environment based on KDE technologies. Supports a number of languages such as C, C++, and Ruby.
Web Development
Quanta+
A feature-rich web development environment with support for various markup and scripting languages, such as HTML, XML, and PHP.
KFileReplace
A very capable multi-line, mutli-file, multi-directory find and replace.
KImageMapEditor
An HTML image map editor for KDE.
KLinkStatus
A link checker for KDE, based in LinkStatus.
KSXLDbg
A KDE GUI for debugging XSLT scripts
Utilities
Kompare
See clearly the differences between two versions of a text file
Kommander
A visual dialog builder that can be used to create applications.
Kate
An advanced text editor with many features including syntax highlighting
