Thanks to everyone,
I finally used meerkartor (which is powerful but needed to close some items to fit my screen ;)
which is a native debian package (aptitude install merkaartor).
A great tool bu that is a little bit annoying with it is you cannot dislocate a POI from a path once it had
collapsed (you'll edit the path together).

Potlatch v1 is also mostly unusable with gnash (pointer is freezing, help and contextual windows displays black except for links, etc)