Currently, MacPerl stands at version 4.1.8 for Perl 4 and 5.0.7r1m for Perl 5. Both versions run best on a Mac with at least 8M of RAM, System 7 or later, and at least an 68020 processor, although MacPerl 4.1.8 can be made to run on an 68000 with 2M of RAM.
The easiest way to get MacPerl is from a CPAN site in the ports/mac subdirectory. For every version of MacPerl, there are three archives: Mac_Perl_XXX_appl.sit.bin contains the standalone application (which is probably what you want); Mac_Perl_XXX_tool.sit.bin contains the MPW Tool; and
Mac_Perl_XXX_src.sit.bin contains the source code distribution.
To subscribe to the MacPerl mailing list, send email to:
mac-perl-request@iis.ee.ethz.ch
whose body consists of the single word "subscribe".
There are a number of WWW pages on MacPerl; as a starting point, I recommend my own page:
http://www.iis.ee.ethz.ch/~neeri/macintosh/perl.html.