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.
TEA is a powerful and easy-to-use Qt4-based editor with many useful features for HTML, Docbook, and LaTeX editing. It features a small footprint, a tabbed layout engine, support for multiple encodings, code snippets, templates, customizable hotkeys, an "open at cursor" function for HTML files and images, miscellaneous HTML tools, preview in external browser, string manipulation functions, Morse-code tools, bookmarks, syntax highlighting, and more.
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.
e3 is a full-screen, user-friendly text editor with an interface similar to that of either WordStar, Emacs, Pico, Nedit, or vi. It's heavily optimized for size and independent of libc or any other libraries, making it useful for mini-Linux distributions and rescue disks. The assembler version supports Linux, FreeBSD, OpenBSD, NetBSD, Win9x, QNX, Atheos, BeOS, ELKS, and DOS. There is also a separately distributed version written in C which supports some other Unix versions and CygWin. It is also possible to use regular expressions by using child processes like sed. e3 has a built in arithmetic calculator.
CMUCL is a free, high performance implementation of the Common Lisp programming language which runs on most major Unix platforms. It mainly conforms to the ANSI Common Lisp standard. CMUCL provides a sophisticated native code compiler; a powerful foreign function interface; an implementation of CLOS; the Common Lisp Object System; which includes multimethods and a metaobject protocol; a source-level debugger and code profiler; and an Emacs-like editor implemented in Common Lisp. CMUCL is maintained by a team of volunteers collaborating over the Internet, and is mostly in the public domain.
Cream is a configuration of the famous Vim text editor that makes it easier to use, like an Apple- or Windows-style text editor. It uses Vim's own extensibility to improve menus, keyboard shortcuts, and editing behavior. Cream seamlessly maintains Vim's insertmode to access all the power of the original Vim plus many custom Cream extensions.
Motor is a text-mode integrated programming environment for Linux. It consists of an editor with syntax highlighting, a project manager, a makefile generator, gcc, ctags, gdb, autoconf/automake and grep front-ends. CVS integration is also provided. It allows one to edit, compile, and debug programs without a need to leave the IDE, automatically check in/out files from a CVS repository and import projects into CVS, and generate distribution packages (tar.gz and RPM). The color schemes are customisable.
dhex is a more than just another hex editor: It includes a diff mode, which can be used to easily and conveniently compare two binary files. Since it is based on ncurses and is themeable, it can run on any number of systems and scenarios. With its utilization of search logs, it is possible to track changes in different iterations of files easily.