#!/usr/local/bin/perl5.10.0
	
my @queue =<<"HERE";
I have some <brackets in <nested brackets> > and
<another group <nested once <nested twice> > >
and that's it.
HERE

my $regex = qr/
		(                   # start of bracket 1
		<                   # match an opening angle bracket
			(?:               
				[^<>]++     # one or more non angle brackets, non backtracking
				  |                  
				(?1)        # recurse to bracket 1
			)*                 
		>                   # match a closing angle bracket
		)                   # end of bracket 1
		/x;

$" = "\n\t";

while( @queue )
	{
	my $string = shift @queue;
	
	my @groups = $string =~ m/$regex/g;
	print "Found:\n\t@groups\n\n" if @groups;
	
	unshift @queue, map { s/^<//; s/>$//; $_ } @groups;
	}