I looked in to this for a college project.
First please not that there are 3 modes of NFC operation { Card read/write, tag emulation and P2P communication }. Android supports Card read/write and P2P communication.
To communicate with a non Android device via P2P is quite complex as you must use the NPP (Ndef Push Protocol) built on LLCP (logical link control protocol). Your non android platform will need to implement the LLCP to be able to communicate. I'm not sure if this has been done for NFC yet. Information on the NPP/LLCP implementation can be found here
The next approach is to use card read/write mode to communicate with the non Android device running in card emulation mode. This way you can send APDU's to the emulated tag to send and receive data. I did this approach in reverse using BlackBerry for my project. BlackBerry supports card emulation so I used the non Android device (ACR122U) to send APDU's to the BlackBerry.
While the first approach (P2P) is obviously the ideal way to go, the second one could be easier to implement. It worked quite well for me in my application anyway, I created a system that accepts payments via NFC.
Please note that the ACR122U doesn't have good support for NFC Tag Emulation so it is not suitable for you. The LibNFC website is a great start to find a device that supports tag emulation.
I am now finished the project and it works great using the ACR122U device. If you need any help on the second approach please ask.