APC: http://pecl.php.net/APC

Benchmarking Laconica PHP 5.2.7-dev
 siege -H "Cookie: rememberme=13A195e06ce1b0c466b62c0d0025611fe72" \
        -c 5 "http://laconica.localhost/index.php?action=public" \
        -b -t30s
** SIEGE 2.66
** Preparing 5 concurrent users for battle.
The server is now under siege...
Lifting the server siege...      done.
Transactions:               1363 hits
Availability:             100.00 %
Elapsed time:              30.04 secs
Data transferred:          14.11 MB
Response time:              0.11 secs
Transaction rate:          45.37 trans/sec
Throughput:                 0.47 MB/sec
Concurrency:                4.99
Successful transactions:    1363
Failed transactions:           0
Longest transaction:        2.95
Shortest transaction:       0.03
Benchmarking Laconica - PHP 5.3.0-dev
 siege -H "Cookie: rememberme=13A195e06ce1b0c466b62c0d0025611fe72" \
        -c 5 "http://laconica.localhost/index.php?action=public" \
        -b -t30s
** SIEGE 2.66
** Preparing 5 concurrent users for battle.
The server is now under siege...
Lifting the server siege...      done.
Transactions:               1406 hits
Availability:             100.00 %
Elapsed time:              30.47 secs
Data transferred:          14.54 MB
Response time:              0.11 secs
Transaction rate:          46.14 trans/sec
Throughput:                 0.48 MB/sec
Concurrency:                4.99
Successful transactions:    1406
Failed transactions:           0
Longest transaction:       20.61
Shortest transaction:       0.02
Habari-0.6 - PHP 5.2.10-dev + APC
Transactions:                794 hits
Availability:             100.00 %
Elapsed time:              29.75 secs
Data transferred:           4.00 MB
Response time:              0.19 secs
Transaction rate:          26.69 trans/sec
Throughput:                 0.13 MB/sec
Concurrency:                4.99
Successful transactions:     794
Failed transactions:           0
Longest transaction:        0.48
Shortest transaction:       0.07
Wordpress-2.7.1 - PHP 5.2.10-dev + APC
Transactions:                999 hits
Availability:             100.00 %
Elapsed time:              30.20 secs
Data transferred:           4.88 MB
Response time:              0.15 secs
Transaction rate:          33.08 trans/sec
Throughput:                 0.16 MB/sec
Concurrency:                4.99
Successful transactions:     999
Failed transactions:           0
Longest transaction:        0.68
Shortest transaction:       0.06
Magento-1.3.0 - PHP 5.2.10-dev + APC
% siege -c 5 "http://magento.localhost/a-widget.html -b -t30s
Transactions:                125 hits
Availability:             100.00 %
Elapsed time:              30.49 secs
Data transferred:           1.83 MB
Response time:             1.21 secs
Transaction rate:           4.10 trans/sec
Throughput:                 0.06 MB/sec
Concurrency:                4.94
Successful transactions:     125
Failed transactions:           0
Longest transaction:        1.63
Shortest transaction:       1.05