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.
AutoLaTeX is a tool for managing small to large LaTeX documents. It detects which files which are used to build the document (included TeX files, BibTeX, figures, etc.), and launches the various different tools (latex, bibtex, makeindex) when the sources files have been changed. It provides translation rules which automatically generate figures in EPS, PNG, or PDF formats from different types of sources (dia, xfig, svg, astah, source code, etc.) AutoLaTeX also provides graphical user interfaces, a plugin for the editors Gedit and Sublime Text, and a standalone Gtk application.
Asymptote is a powerful descriptive 2D and 3D vector graphics language for technical drawing, inspired by MetaPost but with an improved C++-like syntax. It provides for figures the same high-quality level of typesetting that LaTeX does for scientific text. Asymptote is a programming language as opposed to just a graphics program. It can exploit the best features of script (command-driven) and graphical user interface (GUI) methods. High-level graphics commands are implemented in the language itself, allowing them to be easily tailored to specific applications.
tex-upmethodology provides a complete set of LaTeX styles that permit you to write documents according to a UP-based methodology. Its major features are document history, task management, design and specification documentation, and helping tools. tex-upmethodology is officially supported by CTAN.
LyX is a document processor that encourages an approach to writing based on the structure of your documents, not their appearance. It is intended for people people who write and want their writing to look great without tinkering with formatting details, font attributes, or page boundaries. On screen, it looks like any word processor, but it uses the TeX engine for printed output and producing richly cross-referenced PDFs. It is stable and fully featured.
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.
GLE (Graphics Layout Engine) is a graphics scripting language designed for creating publication quality figures (e.g., a chart, plot, graph, or diagram). GLE supports various chart types (including function plot, histogram, bar chart, scatter plot, contour plot, color map, and surface plot) through a simple but flexible set of graphing commands. More complex output can be created by relying on GLE's scripting language, which is full featured with subroutines, variables, and logic control. GLE relies on LaTeX for text output and supports mathematical formulae in graphs and figures.
TeX Live is an easy way to get up and running with TeX. It provides a comprehensive TeX system with binaries for most flavors of Unix, including GNU/Linux, and also Windows. It includes all the major TeX-related programs, macro packages, and fonts that are free software, including support for many languages around the world.