I'm still a complete noob with FPGAs, but as part of my digging around I came across ARM's new DesignStart program. It appears to be a royalty free ARM M0 or M3 core for Altera and Xilinx FPGAs. I thought it might interest a few people here.
https://www.theregister.co.uk/2018/10/01/arm_cortex_m_xilinx/