Now Perl is kept in a version control system called Perforce, which is hosted by ActiveState, Inc. There is no public access to the system itself, but various methods have been devised to allow developers near-realtime access.
Firstly, there is the Archive of Perl Changes. This FTP site contains both the current state of all the maintained Perl versions, and also a directory of changes made to the repository.
Since it's a little inconvenient to keep up to date using FTP, the directories are also available via the software synchronisation protocol rsync. If you have rsync installed, you can synchronise your working directory with the bleeding-edge Perl tree (usually called `bleadperl') in the repository by issuing the command
% rsync -avz rsync://ftp.linux.activestate.com/perl-current/ .
There are also periodic snapshots of bleadperl released by the development pumpking, particularly when some important change happens. These are usually available from a variety of URLs, and always from ftp://ftp.funet.fi/pub/languages/perl/snap/.
Finally, there is a repository browser available at http://public.activestate.com/cgi-bin/perlbrowse which can tell you the current status of individual files, as well as provide an annotated `blame log' cross-referencing each line in a file to the latest patch to affect it.