the command line tool wrjpgcom to write comments to JPEG pictures and jpegtran to do the loss-less rotation;
the command line tools convert, mogrify and composite (or combine) from Image Magick;
jhead to alter the EXIF header and thumbnail and for the automatic lossless rotation
Perl 5.005 or better
Perl/Tk 800.015 or better
Perl module Image::Info
Perl Tk::JPEG (hint: this is already included in Perl/Tk at least since version 804.025)