NewGRF's usually used in the servers can be downloaded from the game inside (more info). However, the servers sometimes use some NewGRF's that can not be downloaded from inside the game. For being able to connect, you must manually download them here.
Spanish train set: steam, diesel, electric engines, along with DMU's and EMU's, and wagons for every type of cargo. The set differentiate the iberic and international gauges, and also suburban, medium and long distance and high speed; finally, several liveries are provided for each train, depending of the year and/or use. Download Spain Set 1.30b.
Spanish train set: steam, diesel, electric engines, along with DMU's and EMU's, and wagons for every type of cargo. The set contains metric gauge trains from Spain. Download FEVE.
Track modification set: substitutes maglev tracks with international gauge tracks. In iberian peninsula scenarios, standard tracks simulates iberian gauge, and the modified (by this set) maglev tracks simulates international gauge. Download Speed Rails.