This facebook page is dedicated to one of the most realistic sci-fi settings in existence. It has 4 incarnations, Traveller:2300 & 2300AD both by GDW, 2320AD published by QLI, and MGT2300AD, published by Mongoose Publishing.
2300AD, Traveller:2300 are the intellectual property of FarFutureEnterprises and 2320AD is owned by Colin Dunn.