FreeBSD is very lucky to have an implementation of tar based on libarchive. This combination has proven to be very fast and is under constant development, kientzle@ has and continues to produce an amazing piece of software.
Perhaps one of libarchive's best kept secrets is its format support which includes tar (of course), cpio, iso9660 (!), zip and now even ar. I dream of seeing rar and write support for iso9660 but that's for another time. Anyway, the fact that libarchive supports zip made me wonder why it wasn't used in Ports. After discussing it briefly on IRC I came to the conclusion that there were fears of regression since zip is not exactly the best defined file format. With that in mind I decided to write a test runner which would fetch every distfile that used zip in the Ports collection and test whether it:
Once I extracted the distfiles list (which I did using a shell script to traverse the ports tree and grep for USE_ZIP, followed by a python script which parsed the output of that and the output of make fetch-list into a dictionary of lists of distfiles), I wrote up a test runner to do the above test case and I'm currently running it. So far it has gone through 26 of 543 ports with two failures that were the result of bad distfiles (I didn't implement distinfo check and retry in the test runner). I will test all the failures by hand once it is done and then if all goes well I will work on a patch to make bsdtar the default tool for doing unzip in the Ports collection!
If anyone is curious I can supply a pickled copy of the distfiles dictionary and the test runner script.