OpenWRT features..

OpenWrt offers all of the features provided in the stock firmware for residential gateways, such as DHCP services and wireless encryption via WEP, Wi-Fi Protected Access and WPA2. In addition it offers features that are poorly-implemented or missing in the standard firmware.
Features include:
a package manager similar to apt-get or pacman. The software repositories contain about 2000 packages chiefly ones suited for environment with limited resources.
extensible configuration of your network involving VLAN with exhaustive possibilities to configure the routing itself
customizable methods to filter, manipulate, delay and rearrange network packets:
firewall
port forwarding of external traffic to computers behind NAT inside the LAN
Quality of service for simultaneous use of applications such as VoIP, online gaming, and streaming media
Traffic shaping for fairly distributing bandwidth between more users
loadbalancing for use with multiple ISPs
ip tunneling
realtime network monitoring and statistics
static DHCP leases
UPnP for dynamically configured port forwarding
use of Dynamic DNS services to maintain a fixed domain name with an ISP that does not provide a static IP address
on devices with USB ports it supports:
printer sharing,
Windows-compatible file sharing (via SAMBA),
USB audio
other devices with available linux drivers
an extensive AJAX-enabled web interface, thanks to the LuCI project
configuration of the device as a wireless repeater, wireless access point, wireless bridge, or a combination of these
mesh networking
regular bug fixes and updates, even for devices no longer supported by their manufacturers
OpenWrt has a fully writable file system, which allows for package management via the opkg package system, allowing users to install new software to meet their individual needs. This contrasts with Linux-based firmwares based on a read-only SquashFS filesystem (or similar) that offers efficient compression but no way to modify the installed software without rebuilding and flashing a complete firmware image. OpenWrt achieves good compression by using mini_fo to overlay a writable JFFS2 filesystem over a read-only SquashFS filesystem in a copy-on-write fashion.
[edit]Web interface