GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.
Kile is a user-friendly TeX/LaTeX editor for the KDE desktop environment. It lets you compile, convert, and view your document with one click and features auto-completion of (La)TeX commands, templates and wizards for starting a new document, easy insertion of many standard tags and symbols and the option to add user defined tags, inverse and forward search, collection of documents that belong together into a project, easy insertion of citations and references, a flexible build system, QuickPreview of selected parts of a document, easy access to various help sources, and advanced editing commands.