Tke is a full-featured and Tcl/Tk-based source code editor. It supports syntax highlighting and auto-indentation for multiple languages. There's support for a Vim mode, code snippet and clipboard management, bookmarks and multiple cursors. Tke provides a tabbed interface with a file system sidebar. It's also NFS and lock aware, extensible per plugins, allows regex searching/replacing, has configurable menus, and allows unlimited undo/redo levels.
Suplemon is a modern, slick and intuitive console text editor with multi cursor support. Suplemon replicates Sublime Text style functionality in the terminal with the ease of use of Nano.
KKEdit is a programmers editor using the Gtk toolkit in the style of Mac BBEdit. It's not an IDE, but provides slightly more coding functionality than other text editors; syntax highlighting, function outlines/jumping, external tool and binding and an inline-shell, remote editing, manual viewing, and remembers editing sessions. KKEdit uses non-flat tabs and icons per default.
KDevelop is a cross-platform IDE. It supports various programming languages such as C, C++, Python, PHP, Java, SQL, Ruby, QML, JavaScript, Go, and document formats XML, HTML, CSS, build systems QMake, CMake, and version control, GUI builders, debugging and documentation tools. It's based on KDevPlatform and the KDE and Qt libraries.