Hi Gerben,

>
> It is probably my lack of brain cells, but I do not understand chapter
> 2 of the ConTeXt manual at all.
>
> Suppose I have a manual-like document and I want to produce different
> PDF-files out of it:
>
> 1. The book
> 2. The book in another layout
> 3. The book in screen format with navigation
> 4. A simple presentation with bullet points, one or more pages per
> chapter
>
> As I understand it I will need 4 environments:

No you can define modes in a single environment file.
Later you can ask texexec to use one ore more of the defined modes.

texexec --mode=mode1
texexec --mode=mode1,mod5
>
> .../foo/bookenv.tex
> .../foo/book2env.tex
> .../foo/bookscreenenv.tex
> .../foo/presentation.tex
>
> and I can put each chapter in a component file, i.e. chapter1.tex,
> chapter2.tex etc.
>
> .../foo/chapter1.tex
> .../foo/chapter2.tex
>
You can do this. It might be worthwhile to think about making the chapter a
product, then you keep the possibility to add components if the size of the
chapters is too large.

> But here my understanding stops.
> - Should I create a project file for each of the 4 modes above? And put
> these in different subdirectories as in:
>
> .../foo/book/book.tex
> .../foo/book2/book2.tex

No, use modes in the environment file.
>
> etc.? Or do I use multiple environments in one project and I can get 4
> PDF's as a result?

texexec --mode=mode-x --result=jobname-mode-x jobname

Or are these multiple products (I would guess this,
> but how then to set it up)? Should my chapter files contain
> \startcomponent \stopcomponent and does that mean they are
> independently compilable?

Any level of the project can be compiled separatly. So you can compile a
component, a product or the project.

>
> I have been reading and re-reading this, but the relation between
> project, environment, component and product keeps escaping me.

The basic idea is not that complicated:

The project(file) is the cuboard
The product(file)s are drawers of the cupboard
The component(file)s are boxes in one of the drawers whithin the cupboard.

Teh environment is used to handle the whole project.

>
> Is there a good example somewhere?
>
Whether is is a good example you will have to decide...

Success Willi