The open source RISC-V architecture is gathering some interest (https://riscv.org/)
For using ARM architecture, ARM charges a license fee in addition to the royalty if their IP is also used.
If the open source RISC-V architecture gets momentum (and for that a lot will depend on how Software ecosystem will grow for same), there could be some threat to ARM.
Read following article for more insights
http://www.extremetech.com/computing/188405-risc-rides-again-new-risc-v-architecture-hopes-to-battle-arm-and-x86-by-being-totally-open-source
thanks
Ramdas
https://www.quora.com/profile/Ramdas-Mozhikunnath
