Lyx is a documental processor that combines, you can say compromise too :), the power and flexibility of Tex/Latex with the ease of use of a graphical interface. It encourages an approach to writing based on the structure of your documents (What is you see is what you mean) and not simply their appearance (What is you see is what you get).
Latex which is typesetting engine for Lyx can obtain high quality, structured, and elegant documents that cannot easily obtained with Microsoft Word. After many years of using Latex, I feel the thinking flow when you writing document seems to be different from Word. If you have a basic knowledge in Tex/Latex, it is very easy to familar with Lyx. I use it from version 1.3 to 2.06 now. It is better and easier for scientist and engineer (maybe except math geek) to use than Latex.
Today I install Lyx in my iMac after I intall MacTex.
