AbiWord
Compose, edit, and view documents
Bibus
manage references and citations in your publications
FocusWriter
Write without distractions
LaTeXila
Edit LaTeX documents
LibreOffice Writer
Create and edit text and images in letters, reports, documents and Web pages by using Writer.
LyX
High level LaTeX frontend
ReText
Simple text editor for Markdown and reStructuredText
Zoho Webservice Word Processor
Create and edit text and graphics in letters, reports, documents and Web pages using Zoho web services.
LyX Document Processor (2.2)
High level LaTeX frontend
Formiko Vim
reStructuredText and MarkDown editor and live html previewer - Vim mode
Formiko
reStructuredText and MarkDown editor and live html previewer

Manuskript
Open source tool for writers

ghostwriter
Distraction-free text editor for Markdown
OpenOffice.org Word Processor
Create and edit text and graphics in letters, reports, documents and Web pages.

GNOME LaTeX
Edit LaTeX documents

Gummi
Simple LaTeX Editor
Notes-Up
Your markdown notebook