yeah, it seems ActiveState 5.8.0 under WinXP, only 256 threads can be created. If Try to start more than that the program exits, no error, no warning. . . .:

use strict;
use threads;

my $num_threads = 0;

for(1..257) {
    my $thr = threads->new(\&threader);
    $num_threads++;
    print "$num_threads started\r";
}

print "$num_threads running\n";
sleep();

sub threader {
    sleep();
}
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