LaTeX is free software under the terms of the LaTeX Project Public License Datazar, and LaTeX base offer the ability to edit, view and download LaTeX files.
Microsoft Windows, Apple Mac OS X, Linux including Ubuntu: The comprehensive cross-platform LaTeX distribution TeX Live can be downloaded here.
Installer. To install a basic TeX/LaTeX system on Windows, download and run this installer. Please read the tutorial, if you want step-by-step guidance.
[OPTIONAL] Download and install Ghostscript (and Ghostview if you want it). You don't need this if you just use pdflatex, but you might want to get it to keep your.