There's a first time for everying

flub@signy:~/src$ tar -xzf storm-0.10.tar.gz

gzip: stdin: not in gzip format
tar: Child returned status 1
tar: Error exit delayed from previous errors
flub@signy:~/src$ file storm-0.10.tar.gz
storm-0.10.tar.gz: POSIX tar archive (GNU)
flub@signy:~/src$ mv storm-0.10.tar.gz storm-0.10.tar
flub@signy:~/src$ tar -xf storm-0.10.tar
flub@signy:~/src$

I don't think I've ever had an incorrectly compressed tarball before. Storm offers the download in .tar.bz2 and .tar.gz, but at least the .tar.gz is not compressed at all (not that it is necessary with 804kB) and I didn't try the other one.

It is just a fairly bad first impression...

Update

It seems the download file is actually correct as pointed out in the comments. It's not just a simple human error, it's a most interesting little bug of launchpad.