NEdit is described as 'multi-purpose text editor for the X Window System, which combines a standard, easy to use, graphical user interface with the thorough functionality and stability required by users who edit text eight hours a day' and is an app in the Development category. There are more than 25 alternatives to NEdit for a variety of platforms, including Windows, Linux, Mac, BSD and Chrome OS. The best alternative is Visual Studio Code, which is free. Other great apps like NEdit are Atom (Free, Open Source), Sublime Text (Paid), Vim (Free, Open Source) and VSCodium (Free, Open Source).
VS Code is more than just a code editor, it provides the tools and extensions to compile, debug, compare, refactor, and even manage code repositories all within a highly-customised development environment.
The Kate project develops two main products: KatePart, the advanced editor component which is used in numerous KDE applications requiring a text editing component, and Kate, a MDI text editor application.
Bluefish is a powerful editor targeted towards programmers and webdesigners, with many options to write websites, scripts and programming code. Bluefish supports many programming and markup languages, and it focuses on editing dynamic and interactive websites.
CudaText is a cross-platform text editor, written in Lazarus. It starts quite fast (0.5 sec with ~30 plugins on CPU Intel Core i3 3Hz). It is extensible by Python add-ons (plugins, linters, code tree parsers, external tools).