greenbytes.de
Test Cases for HTTP Content-Disposition header field (RFC 6266) and the Encodings defined in RFCs 2047, 2231 and 5987
Historically, it was impossible to send filenames containing non-ASCII characters without doing browser sniffing, and varying the response based on the detected browser. With the work leading to RFCs 5987 and 6266, and the subsequent improvements in IE and Chrome, and finally in Safari 6, the sitution has improved a lot.