OpenWrt is a highly extensible GNU/Linux distribution for embedded devices (typically wireless routers).
Unlike many other distributions for these routers, OpenWrt is built from the ground up to be a full-featured,
easily modifiable operating system for your router. In practice, this means that you can have all the features
you need with none of the bloat, powered by a Linux kernel that's more recent than most other distributions.
Source: https://openwrt.org/about