Using this code as a base and later as a reference, developers created a Linux distribution that offers many features not previously found in consumer-level routers. Early on some features required proprietary software. For example, prior to OpenWrt 8.09 (based on Linux 2.6.25 and the b43 kernel module) WLAN for many Broadcom-based routers could only be had via the proprietary wl.o module (and which required Linux 2.4.x).