I was interested in "kangaroo"; Wikipedia suggests a kangaroo word should, in addition to having the same letters and in the same order as its parent, also have the same meaning (eg. masculine -> male), so "parse" isn't quite a kangaroo for "parsley", apparently. It'd be a moderately fun little challenge to write a little program to find some kangaroos - though Wiktionary (predictably) has a nice list already here: http://en.wiktionary.org/wiki/Appendix:Kangaroo_words
"Parsley" is indeed a great name. I'll contribute another Parsley - a Flex framework of yore also bore that name.
I'm afraid there's https://github.com/darius/parson already too. (I went through the same process to name it -- there's not much left in that well, is there?)
First commit on fizx/parsley was in 2008. The library was open-sourced in 2009. This predates all of the name conflicts so far mentioned, though no doubt someone used the name before in some capacity.
https://github.com/cgrand/parsley