WebSpell is a complete HTML-aware spelling checker which is compatible with Ovation Pro user dictionaries.
It comes in two forms - one is a plugin for HTMLEdit which allows in-page checking and the other (on the same disc) is a stand alone solution with the ability to check multiple pages at once.
WebSpell will support multiple languages including Dutch and German, and can translate &xxxx; notation as used by HTML to represent foreign characters.
Single: £15; Site: £40.