The stuff which makes perl really awesome are the distributions on CPAN.
Many (though not all) of these distributions contain XS, which is a type of glue between perl and C. Most of these XS distributions are there to link to some library -- Math::GMP, for example, lets perl code use the GNU gmp multi precision math library.
Without some way to make use of distributions with XS parts, then a perl to $other_language_here transpiler is not going to be very interesting.
That makes sense. Library compatibility is a tough issue to deal with. Scala.js faces the same issue when it comes to libraries that depend on the Java stdlib. I believe their goal is to port the entire stdlib, but I'm not sure tbh. It might just be an insurmountable problem.
Actually quite few are XS and XS is painful/a terrible way to plug C code inside of the Perl interpreter's guts. For this reason Perl6 aims to rewrite most of the stuff in Perl6/NQP and use NativeCall to call on external libraries.
Themgt, it's obviously a matter of legality, not practicality.
Chrome's rules are that no plugins in their store may do illegal things, so if Youtube says that Streamus isn't compliant, then Streamus can't be in the Chrome Web Store.
That doesn't prevent us who already have the plugin from continuing to use it, it's merely a violation of youtube's license agreement to do so.
