Other RFID systems.
The StaRFIshrail system was designed to overcome what I perceived as the problems associated with other RFID solutions, especially regarding multiple RFID points. However, as it was also designed by a hobbyist for other hobbyists, you should be aware that other RFID solutions are available, investigate them yourself, and make up your own mind. I am not trying to do a hard sell - I would hate to think that a fellow hobbyist has spent their hard-earned money on a system which does not do what they want, or does not fit the bill.
StaRFIshrail is not the only solution to RFID in model railways, as each user will have different requirements, but not everyone will want to experiment and tinker with RFID, some will want to install a working system with no fuss.
Please also note that StaRFIshrail is not compatible with any other (known) RFID system for model railways. Others are using 13.56MHz, but, as far as I can tell, all use the MIFARE ISO14443 standard. StaRFIshrail uses the ISO15693 standard, for reasons explained on the "StaRFIshrail Difference" page in Technology.
This is probably not an exhaustive list of other systems, use Google or Duckduckgo or Bing search engines yourself, but these are the first search results to appear.
MERG (Model Electronic Railway Group) have been working on RFID for many years, having produced kits for a 125KHz system. There is now much discussion and work taking place with RC522 readers (which are 13.56MHz, like StaRFIshrail, but incompatible). The RC522 readers are spectacularly cheap, being of Chinese origin, and I would encourage any of you who wish to experiment with RFID to become MERG members, and follow the discussions. Only MERG members can purchase kits, but membership is cheap.
Traintraxx is a HiveID based solution, and has some clever software for inventory control. The only views of aerial installation on their website show a pcb aerial installed immediately beneath the tracks, and for multiple RFID points, the whole system is quite expensive. The company is based in the USA, but does do International shipping.
This system uses 125KHz tags, which are essentially slow - they cannot reliably detect trains running at high speed on a main line. This was the original RFID system, but again, is expensive for multiple RFID points. Another USA company, International shipping is available.
CTI Electronics do a RFID sensor for their TrainBrain system - part TB017. Again, this is very expensive for multiple RFID points, and the tags are not cheap either. Again, a USA based company with International shipping.
Rocrail is a complete train control system, and various modules are available for building. Their RFID modules use RC522 readers, and are sold through Giling Computer Applications in the Netherlands. Note that StaRFIshrail is compatible with RocRail control.
Eccel produce a range of commercially available RFID modules, some of which may be suitable for model railways. The McKinley Railway appear to be using some of these - you can find videos on youtube.