Thank's Leaf85! Trainz looks real promissing and the link you gave me has good freeware content for it.
I hadn't much time to look at the train sim community the last few years, cause of my other simulation project, but since I could not do so much with it at the moment, I did a bit of research in the genres I also liked very much back those days.
I was a little bit shocked as I have seen that nearly no one still uses the MSTS. O.k. time goes by. Mhmm maybe a lot of time
So I looked for an alternative, because I occasionally would like to play a train sim again, but don't want to spent so much money for it. For the MSTS there was a lot of good freeware content also available back those days, but not so for the Dovetail Train Simulator as far as I have seen.
Yes, Open Rails is useable with the MSTS, at least it was the fact the last time I used it a few years ago. I have to take a look what changed. Maybe I could save my old MSTS from aging with it a little bit.
And perhaps I will also take a closer look to Trainz. Looks more friendly to me than TS.