Gallium Nine definitely existed prior to Valve’s involvement, but they funded DXVK for sure and DXVK replaced Nine for all intents and purposes. Nine was a great early attempt at bringing fast D3D9 to Linux but required custom drivers and didn’t work for all GPUs. Valve’s efforts have still been very noteworthy on Linux, over the past 15 years Linux gaming has gone from a pipe dream outside of a select few OpenGL-based games to a true competitor in the gaming OS space and it’s in big part thanks to Valve.