From time to time I want to present some of the software I use here. Today it is:

GNU TeXmacs

What is it?

GNU TeXmacs is a wysiwyg editor with LaTeX import/export. It handles the typographical needs of those who need to type complex formulas, does automatic referencing and bibliographies without the need to know LaTeX. Moreover it allows you to type mathematics really fast and frictionless due to congenial on-the-fly composing of symbols.

What is real world use?

I use GNU TeXmacs for shorter and longer mathematical writing, i.e., from exercise sheets to complex documents. I have written major parts of my phd thesis with TeXmacs and drafts of articles for mathematical journals. Why only major parts of my thesis? Well, sometimes you have to meet certain standards, e.g., use special LaTeX classes and so on, but TeXmacs is my first choice in those cases as well. You can rapidly prototype your text in TeXmacs and export to LaTeX for fine-tunning and adjusting to the necessities. Daniel Bump wrote an excellent book an Lie groups in the Springer Lecture Notes in Mathematics series in that way.

What to try first?

You should try composing formulas first, just to get an impression, cf. Help -> Manual -> Mathematical Formulas in the menu. Insert a $ and type the following sequence on your keyboard (words in CAPS refer to the corresponding keys on the keyboard and the white spaces are just for readability)

( x _ n RIGHT_ARROW ) _ n < TAB TAB TAB SHIFT+F6 N

and you will end up with a nicely formatted formula of natural numbers. This looks more complicated than it is, but is much faster than writing down the corresponding LaTeX

(x_n)_{n \in \mathhbb{N} }.

You have to try to believe :-).

But that is by no means all the goodness there is to TeXmacs. For instance you can use interactive sessions like shown below for Shell, maxima, python, R and many more:

There is also a very nice plot mode:

Where is additional information?

GNU TeXmacs has a web site at www.texmacs.org which is written in TeXmacs as well and exported to html. It is a GNU project and you can find the sources on Savannah www.gnu.org/software/texmacs.

What is the license?

GNU TeXmacs is licensed or GPL version 3.

Any possible caveats?

Be aware that using GNU TeXmacs may be quite addictive and may really spoil the fun of writing direct LaTeX. Additionaly, there is a bug in recent version which breaks the TAB use in Ubuntu/Kubuntu, if you start TeXmacs from the menu. Starting it from a terminal solves this issue as a temporay workaround.

What will TeXmacs be like in the near future?

It will be based on QT. There is a QT port which is almost done, but just is not quite ready for productive use right now. It will look like this: