Early 2.6, continued

2.6.4 (March 10, 2004)
Intel ia32e architecture support
Dynamic PTY support
Large number of groups support

2.6.5 (April 3, 2004)
Netpoll interface
dma_sync_* API change
Hotplug CPU support

2.6.6 (May 9, 2004)
Laptop mode
POSIX message queues
Non-executable stack support
Lightweight auditing framework
TCP "vegas" congestion avoidance