When Norway (unfortunately) privatized and tenderized* the railway, they at least made a provision that every ticket should be purchaseable through a government owned entity. Which means you can use the government app ("Entur") to travel plan and purchase, even between operators and even modalities (trains, busses, trams, etc).
* (using the word wrongly), and it was a hack job. The existing operator is still owned by the government (NSB, renamed to Vy), but then had to bid on contracts to win their existing lines back. Which they of course were predetermined to lose most of, otherwise all that work from the right side government would have been useless.
Of course, NSB then also couldn't have any advantages having been the sole provider from before. So men in suits decided which IT systems they were allowed to keep, and which should be the basis for the Entur app/system.
I came in as a consultant at Vy to reimplement what got severed, without having any prior knowledge/advantage.
So much weirdness, and so much waste