Standard inline-block vs. Firefox -moz-inline-box

Could someone sum up the difference(s) between the standard CSS
display: inline block and the non-standard Firefox (Mozilla) display: -
moz-inline-box?

I have used the following in a couple of special situations to render
inline elements (like A and SPAN) as block elements that flow with
inline items and it seems to work, although I know I shouldn't depend
on such:

<style>
.special {
display: -moz-inline-box; /* Ignored by IE */
display: inline-block; /* Ignored by FF */
}
</style>
This is <a href="#" class="special" style="width:100px">interesting</
a> because the link acts as a block in both IE and FF.