When I started writing Swoooosh, the main reason was that after needing a free component for a project for a customer of mine (where uploading multiple files were not an original part of the specification, but was added later), I were left with a few components with dubious licenses and weird attribution requests that left you guessing. Instead I hoped someone would release something under an MIT-based license (or LGPL, BSD, etc) to be free for all kinds of usage, and could be further extended by the community.
Luckily a few alternatives has emerged since then, and Swoooosh isn’t really that relevant any longer (it was a good exercise for writing Flex and ActionScript, tho):
And Yes, Christer, I’m going to implement one of these and commit to SVN any moment now. :-)