If you are not that interested in efficiency, Perl has nice magic to do what you want :

perl -le "$a='AAAAAAAAAA'; while ($a lt 'zzzzzzzzzz') { print $a++ }"
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There is only a small problem with my solution - it won't work with numeric strings like starting at 0000000000 and not for strings looking like a number or ending in something that looks like a number - so for these, you will have to come up with another solution. Here is a small hint to that - a string can be interpreted (for example by pack and unpack) as a number in the base of your current alphabet, just like a number in decimal notation is written in an alphabet of 10 letters (0..9). So you can take the number 0, interpret it in your alphabet of digits a..z, A..Z, 0..9, print it, then increment it and so on.

perl -MHTTP::Daemon -MHTTP::Response -MLWP::Simple -e ' ;    # The  
$d = new HTTP::Daemon and fork and getprint $d->url and exit;#spider
($c = $d->accept())->get_request(); $c->send_response( new   #in the
HTTP::Response(200,$_,$_,qq(Just another Perl hacker\n))); ' #  web
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