TeX/LaTeX is great, I use it in many ways. Some of it's advantages are:
it uses text files, this way the input-files can be diffed and many tools exist to work with text
it is very flexible
it has a stable layout: if I change something at the start of the document, it doesn't affect other things at the end of the document
it has many extensions to reach different goals (a successor would start without extensions, but would have a good extension-system)
you can use standard build control tools to support complicated documents (thanks dmckee)
you can encapsulate solutions and copy&paste them to new documents or send them to others to learn from (thanks dmckee)
But on the other hand some little things are not so good:
it is hard to learn at the beginning
it is complicated to control position of images
a few things are a little counter-intuitive
sometimes you have to type too much (begin{itemize} ... \end{itemize})
So, does there exist a successor/alternative to LaTeX or at least is some hot candidate for an alternative in development. A real successor/good alternative would keep the advantages and fix the disadvantages, or at least some of them.
