Comment 6 for bug 170275

I've just downloaded and tried Expression
(http://www.microsoft.com/products/expression)

It has a different approach, but the idea is very similar. In
Expession you can represent a path with another path(more
simple). It's like the Inkscape linked offset but you can use
any path.

This is also a good aproach, it lacks the advantages of
defining a hierarchy, but it requires less new elements to
implement, because it can be defined with the existing tools
Inkscape has.

They are called Skeletal strokes, and that's a little description
I quote from the manual in case my description were difficult
to understand:

"Skeletal Strokes is the kind of user-definable stylish brush
strokes made from arbitrary vector or bitmap pictures. Skeletal
Strokes are applied along a path, also referred to as the
skeleton of the stroke, and can be easily controlled by
manipulating the path itself.

Graphics of any design can be easily turned into a
Skeletal Stroke. All you need is a quick simple marqueeing
gesture using the Stroke Definition Box tool. Whether a
atercolor brush trail, a fish, an arm or a picture created from
other Skeletal Strokes, they can all be turned into new
Skeletal Strokes, and be used for drawing at once.
In Expression, Skeletal Strokes are always in your
control. You can make different parts stretch or
repeat differently, or use multi-view strokes to add
variety or make animations."

--Pau