London Underground ticket machines using old National Rail fares?

[Deerfold]

It's a shame that the Oyster system is proprietary. When it was introduced, weren't there any open standards for stored-value transport cards? If not, why didn't TfL make the system an open standard to avoid vendor lock-in and to encourage competition?

As in so many cases, the contract was signed before TfL existed. TfL had to buy the rights to the brand from Transys (in 2010). The technology was developed by Cubic, which answers many of the other questions.