Texmacs is the dream. 4/5 stars only bc of minor bugs like problems with PDFs and hyperlinks. Very user friendly and learning curve is quick for shortcuts that makes your life really easy. Very productive. My main editor for reports on college now.
Highly useful for producing quickly LaTeX-quality documents. This is my main editor for scientific documents. Its capability to integrate inside a typeset document computing sessions in various languages (Python, Maxima, ...) is also very nice. I recommend it to all my colleagues.
A great scientific editor, it works too as a GUI for a lot of apps like Maxima, gnuplot, R, Axiom, etc.