My favorite project of the year may be Schwern's perl5i. His goal is to fix as much of Perl 5 in one swoop. Unlike my Modern::Perl, he's not limiting himself to core modules and pragmata. Anything on the CPAN that fixes a deficiency or problem in the language is fair game.
That goal may remind you of the goals of modern Perl.
The i stands for imaginary in the same way that the square root of negative one is an imaginary number. (Yes, clever Reddit and OSNews kiddies. It can also stand for "irrational", thus Perl 5 is irrational. Your scathing wit withers discussion. Have a lollipop.)
This is important for several reasons.
First, it's a great, grand experiment to discover what Perl 5 could be right now. It's a great language and you can do amazing things with it, but it has its flaws. What if someone could correct them? Perl 5.10.1 won't fix them. Perl 5.12 probably won't. The DarkPAN is too big and scary to change Perl 5's defaults all even by the time of Perl 5.14 -- but if you choose to use perl5i, presumably you know what you're doing. What would the language look like and how would it work then?
Perhaps some features will make their way into the core.
Second, it's a great, grand opportunity to make sure that all of these new pragmata and features and syntaxes work together nicely. It's much easier to makechanges now -- to discover incompatibilities and subtle infelicities -- when they all get used together. Better yet, the perl5i hackers can file bugs and work with individual distribution maintainers to seek out consensus and compatibility.
Third, it's a great, grand educational tool to demonstrate corners of CPAN that deserve far more popularity than they have. For example, today I suggested the use of the Want module, which fixes a poorly named core keyword and extends it to greater utility. This module may even help the included
autobox::Core handle reference contexts appropriately.
Right now it's not stable; it's experimental. It's worth downloading and testing in your own code, however. Write software. See what happens. File bugs. Suggest new features. See what's compatible and what isn't. Explore. Explain. Enjoy.