Thanks Simos. I gave the 7za command line tool a try, and it seems to work quite well, and handily solves the cross-platform unicode filenames problem. (it either correctly figured out that my ext3 filenames were utf-8 based on the locale, or else it just hard assumed utf-8 period. I'm fine with either case, didnt review the source to see which it was... )
I suppose the answer then is to steer clear of the most popular archive formats when you want to release an archive containing unicode filenames to a multi-platform audience. Alternatives, such as 7zip appear to work quite correctly. I found this on wikipedia: http://en.wikipedia.org/wiki/Comparison_of_file_archivers So we have a handful of valid choices after all. > Try with 7zip to extract the said files. I would appreciate it if you could > report back on this. > > Talking about 7Zip, 7z is another option as well. >