UPDATE: It looks like you don’t need anymore to physically rotate your pictures with Firefox/Opera/Chromium in Linux. For instance it did not work with Chromium Version 73.0 but it does with Chromium Version 83.0. I have reconsidered the scripts I use to put my pictures online and found that the reason why it didn’t work was a call to ImageMagick’s "mogrify -auto-orient" which I used to resize the original image for web usage. Now I call mogrify without this option and I have no problem in recent browsers, as long as the orientation provided by you camera is OK of course, which is usually the case. So normally you don’t need exiftran nor jpegtran nor exifautotran anymore. Period.
OBSOLETE: AFAIK image rotation is still needed in 2020 in browsers but jpegtran does the job quite as well as exiftran. jpegtran keeps all tags as long as the "-copy all" option is used, which is not brand new: it has been possible since version 6b of libjpeg, released 27 March 1998. If you always require tag/marker conservation, you can use an alias:
alias jpegtran='jpegtran -copy all'
You can also keep comments only using "jpegtran -copy comments". In place editing is not supported with jpegtran but of course this is a no-brainer as well. You can also use exifautotran which performs the automatic adjustment.
So IMHO you just don’t need to install exiftran, which is a separate program, and just use jpegtran, which is bundled with libjpeg.
P.S. It is not nice to spread misinformation to deprecate the competitors ;-)
jpegtran
and its derivatives can take this flag and actually (losslessly) rewrite the image so that it's oriented differently — making it appear in the correct orientation always. The question here is whether that's still needed, or if significant % of client software is now "smart enough" itself. – mattdm May 27 '15 at 1:15