This is an improved version of ppencode. Like ppencode, this generates a Perl script which only uses Perl's (lowercase) keywords. Instead of printing the encoded string, this version evals it. So, you can convert any Perl script to a Perl script which only contains Perl keywords separated by whitespace. Believe it or not, I think this is a significantly more complex task than the original ppencode.
This means Perl is Turing complete only with keywords, which means you can write a Quine only with keywords.