The Raspberry Pi uses an older ARMv6 core which is not well supported by modern software. In particular, Mono's JIT apparently doesn't support the hardware-accelerated floating point instructions used by that version of the ARM instruction set. The solution is apparently to use the soft-float version of Raspian that emulates floating point instructions in software (which will be extremely slow). However, trying to compile the current version of the F# sources on Github using the stock Mono (2.10.8) fails with the following null reference exception from within the F# compiler: error FS0193: internal error: Object reference not set to an instance of an object Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object at Microsoft.FSharp.Core.FSharpFunc`2[Microsoft.FSharp.Collections.FSharpList`1[System.String],System.String].InvokeFast[CcuThunk] (Microsoft.FSharp.Core.FSharpFunc`2 func, Microsoft.FSharp.Collections.FSharpList`1 arg1...