TexPoint is a Microsoft Powerpoint and Word add-in that enables the easy use of Latex symbols and mathematical formulas in Powerpoint presentations and Word documents.
PGF is a TeX macro package for generating graphics. It is platform- and format-independent and works together with the most important TeX backend drivers, including pdftex and dvips. It comes with a user-friedly syntax layer called TikZ.
LaTeX is a high-quality typesetting system; it includes features designed for the production of technical and scientific documentation. LaTeX is the de facto standard for the communication and publication of scientific documents.