See LEDE website, they have some generic introductory propaganda and per-device specifics. TD;DR: customizable Linux distribution with package manager, tons of

See LEDE website, they have some generic introductory propaganda and per-device specifics. TD;DR: customizable Linux distribution with package manager, tons of features and ongoing support. In my experience less bugs than vendor firmwares, but I always took care to buy hardware known to work well with it.