Here is some Dart code for doing MD5, though at this point in time, MD5 is becoming obsolete in favor of SHA1. But as I have done code for MD5 in other languages I figured I would duplicate the code for another comparison. To look at the languages, checkout MD5 hashing in Python, Ruby and Groovy and MD5 hashing in CoffeeScript, Perl and Scala.
I do like how you can use Method Cascades, this is something that I really wish Java had in it because the code is much cleaner in my opinion.
Got a way to make the code better? Fork the Gist or comment on Github.