users provide articles with formatted text

hi,
i'd like to give the possibility to my website users
to publish their own articles made with formatted text
and an image.

they want to write the text connecting directly to a page
that provide them a html editor.
(one can select text and put it in bold or italic or underlined
and so on). (see www.peppe.info/articoli)

unfortunately it seems to work only on internet explorer for win.
no other browser/platform works.

is there another solution to that?

thanks in advance