The slides from my keynote at PHP NW 2011, about how every great breakthrough is built on the work that has come before it.

1. How To Stand On The Shoulders Of

4. Open Source
Hardware Platforms
Academic

6. “The best
way to
predict the
future is to
invent it.”
- Alan Kay

9. Discover
Research
Produce

10. BCPL
GET "libhdr"
LET start() = VALOF
{ writes("Hello world*n")
RESULTIS 0
}

11. B
main()
{
a 'Hello world' ;
putchar (a);
putchar ('*n');
}

12. C
#include <stdio.h>
int main(void)
{
printf("hello, worldn");
return 0;
}

13. PHP/FI
<? if(!$PHP_AUTH_USER) {
Header("WWW-authenticate: basic
realm="My Realm"");
Header("HTTP/1.0 401 Unauthorized");
echo "Cancelledn" exit;
} else {
echo "Hello $PHP_AUTH_USER.<P>";
} >

14. PHP 3
<? function hitcount($counter_file){
if ( file_exists($counter_file) ) {
$fp=fopen($counter_file,"r");
$count=0+fgets($fp,20); fclose($fp);
}
$fp=fopen($counter_file,"w");
fputs($fp,$count++); fclose($fp);
return ($count);
} ?>

16. QuickSort 1960
function qsort($nums) {
if(count($nums) < 2) {return $nums;}
$pivot = array_rand($nums);
$p1_val = $nums[$pivot];
unset($nums[$pivot]);
$less = $more = array();
foreach( $nums as $n ) {
if($n <= $p1_val) { $less[] = $n;}
else { $more[] = $n; }
}
return array_merge(qsort($less),
array($pivot_val), qsort($more));
}

18. Dual Pivot QuickSort
2009

19. function dsort($nums) {
if(count($nums) < 2) {return $nums;}
$p1 = array_rand($nums);
$v1 = $nums[$p1]; unset($nums[$p1]);
$p2 = array_rand($nums);
$v2 = $nums[$p2]; unset($nums[$p2]);
if($v1>$v2) list($v1,$v2)=array($v1,$v2);
$s1 = $s2 = $s3 = array();
foreach($nums as $n) {
if ($n <= $v1) { $s1[] = $n; }
else if($n <= $v2) { $s2[] = $n; }
else { $s3[] = $n; }
}
return array_merge(dsort($s1),array($v1),
dsort($s2),array($v2),dsort($s3));
}

20. Van
Jacobson
“...is said to have
saved the Internet
from collapsing
due to traffic in
1988-1989”
- en.wikipedia.org/
wiki/Van_Jacobson

21. Discover
Research
Synthesise
Produce

24. “The whole field had suffered blinders; in some sense
search really did need two people who were never
tainted by people like me to come up with that shake up”
– Amit Singhal, Bell Labs

31. Thank You

32. Image Credits
Skater http://www.flickr.com/photos/eyedeaz/5004084713
Martin Richards http://www.cl.cam.ac.uk/~mr10/
Ken Thompson http://cm.bell-labs.com/who/dmr/picture.html
Dennis Ritchie http://www.bobdbob.com/hcc/halloffame/halloffame.html
Rasmus http://www.flickr.com/photos/wafer/365664702/
Zeev & Andi http://www.flickr.com/photos/sebastian_bergmann/52408671
Lorna http://www.flickr.com/photos/myrtti/6052575049
Clock http://www.flickr.com/photos/indraw/4857101224
TBL http://www.flickr.com/photos/tanaka/3212373419
Turing http://www.flickr.com/photos/thurm/1554383213