From Libregamewiki

Reason why OpenTTD is allowed because it doesn't come with the proprietary media.--Kiba 15:23, 25 August 2007 (CEST)

Shouldn't this be counted more as a free engine than a free game then? 83.252.24.157 12:17, 11 September 2007 (CEST)

I agree. The Quake games aren't distributed with the source. The binaries are distributed with the data and the official source is distributed by itself. Any yet, Quake is on the engines list and not the free game list.