LyX!

Writer, part of the Apache OpenOffice suite, is an open-source word processor. It supports the ISO standard Open Document Format (ODF) for data interchange as its default file format, as well as Microsoft Office 97-2003 formats, Microsoft Office 2007 format (ability to "open" documents in version 3), among others.

AbiWord is a free software word processor. The name "AbiWord" (pronounced "Abby Word") is derived from the root of the Spanish word "abierto", meaning "open". It runs on Linux, Mac OS X (PowerPC), Microsoft Windows, ReactOS, BeOS (unsupported), AmigaOS 4.0 (through its Cygnix X11 engine), and other operating systems. Multilingual Portable version (15MB installed) from http://portableapps.com/apps/office/abiword_portable .

Pages is a streamlined word processor and an easy-to-use page layout tool for the Mac. It allows you to be a writer one minute and a designer the next, always with a perfect document in the works.

Texmaker is a free LaTeX editor, that integrates many tools needed to develop documents with LaTeX, in just one application.

TeX Live is an easy way to get up and running with the TeX document production system. 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.

Overleaf, formerly WriteLaTeX, is a collaborative writing and publishing system that makes the whole process of producing academic papers much quicker for both authors and publishers.

MiKTeX is a typesetting system for the Windows operating system. The distribution includes TeX, pdfTeX and XeTeX.Significant features of MiKTeX are its ability to update itself by downloading new versions of previously installed components and packages, and an easy installation process. Additionally, it can ask users whether they wish to download any packages that have not yet been installed but are requested by the current document.

Authorea is the online document editor for researchers that allows researchers to write, cite, host data, and publish research documents. Authorea is trusted worldwide by leading researchers writing and publishing content in every discipline, from astrophysics to zoology. The online document editor supports a wide range of markup languages (richtext/Word, LaTeX, and Markdown) and scientific integrations, including the most popular citation management, graphing, and visualization plugins. Authorea is on a mission to accelerate science through a superior web-based research-writing platform that delivers the power to write and publish in a web-first world squarely to the author.  »

Fidus Writer is an online collaborative LaTeX editor especially made for academics who need to use citations and/or formulas. The editor focuses on the content rather than the layout, so that with the same text, you can later on publish it in multiple ways: On a website, as a printed book, or as an ebook. In each case, you can choose from a number of layouts that are adequate for the medium of choice.

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, graphics, mathematics, interactive content, etc.). The rendering engine uses high-quality typesetting algorithms so as to produce professionally looking documents, which can either be printed out or presented from a laptop.

TeXnicCenter is a feature rich and easy-to-use integrated environment for creating LaTeX documents on the Windows platform. Its powerful editor and its tight integration with the LaTeX environment helps you to concentrate on what matters: The content of your document. And best of all: TeXnicCenter is open source software and available completely free of charge!

Texpad is a LaTeX editor designed for straightforward navigation of projects of any size. When Texpad opens a document it scans through it, looking for LaTeX structure commands and any included files, then it presents you with an outline view with which you can swiftly navigate the entire project.

Kile is a TeX/LaTeX editor providing a user friendly environment to edit TeX/LaTeX source code.

The TeXworks project is an effort to build a simple TeX front-end program (working environment) that will be available for all today’s major desktop operating systems—in particular, MS Windows (XP and Vista), typical GNU/Linux distros and other X11-based systems, and Mac OS X. It is deliberately modeled on Dick Koch’s award-winning TeXShop for Mac OS X, which is credited with a resurgence of TeX usage on the Mac platform.