http://www.babelfish.altavista.com/
using OmniWeb-5.5.4-beta-1-v607.16
Grab some suitable Asian text. I recommend "Chinese (simplified)" and "Chinese (traditional)" from the bottom of
http://developer.apple.com/ -- two similar strings of four glyphs, the one with the complicated second glyph is "Chinese (traditional)". Paste into the the Babelfish form and translate.
Using OmniWeb or the current Safari, one gets variously "A- A-", "S- S-", or "????". Using Firefox 1.5.0.8, one gets eg "Traditional Chinese".
According to tcpflow, the HTTP method is POST, the Content-Type is application/x-www-form-urlencoded, and there is a suitable content length header.
Message body sent by OmniWeb:
doit=done&intl=1&tt=urltext&trtext=%E7%B9%81%E9%AB %94%E4%B8%AD%E6%96%87&lp=zt_en&btnTrTxt=Translate
Message body sent by Firefox:
doit=done&intl=1&tt=urltext&trtext=%26%2332321%3B% 26%2339636%3B%26%2320013%3B%26%2325991%3B&lp=zt_en &btnTrTxt=Translate
It appears OmniWeb and Safari are sending 8bit data, and Firefox is doing something else.