This week, we at Opal Kelly Incorporated announced the release of SYZYGY, a new peripheral interface specification for FPGA systems.
Cue XKCD #927
https://xkcd.com/927/Right--we understand that it's another standard, but there aren't a lot of standards in this specific space--and it's something that we (and our customers) have continually found a need for higher performance peripherals at a price point way lower than FMC for implementation.
Try it, you just MIGHT like it--or at least appreciate that there's another tool in the toolbox.
"We envision SYZYGY occupying the space between present standards where pin economy, low cost, and high performance converge. SYZYGY is free to license to encourage consistency, proliferation, and a healthy ecosystem where carrier and peripheral manufacturers, semiconductor device manufacturers, educational institutions, and research organizations are invited to develop their own additions".
SYZYGY offers higher performance and higher pin count than Digilent's PMOD but without the expense and ultra-high pin count of FMC.
We have also created a dedicated website with additional information to spread the word. You can download the spec and find other pertinent info there.
http://syzygyfpga.io/