If you're interested, I'm at PyCon in Dallas this weekend and would be glad to show off the code if you're here, too. (I may end up doing a 5-minute lightning talk about it). If this interests you, or if you want a copy of the JST => Javascript compiler, send me an email or leave a comment. Just to whet your appetite, here's a sample template that makes three really big nested tables (outer tables are 5x5, each cell of which is another 5x5 table). Using JST, these tables can be rendered by Firefox in less than 2 seconds.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Hi there</title>
</head>
<body>
<h1>This is my template test: $v.name, ${[1,2,3].length} ${[1].length}</h1>
<? function foo() { ?>
<table border="1">
<? for(var i = 0; i < 5; i++) { ?>
<tr>
<? for(var j = 0; j < 5; j++) { ?>
<td>
<table>
<? for(var k = 0; k < 5; k++) { ?>
<tr>
<? for(var l = 0; l < 5; l++) { ?>
<td>($i,$j,$k,$l,${{a: '1',b: '2',c: '3'\}.c})</td>
<? } ?>
</tr>
<? } ?>
</table>
</td>
<? } ?>
</tr>
<? } ?>
</table>
<? } ?>
<? foo(); foo(); foo(); ?>
</body>
</html>
