How this compare with Netmap? http://info.iet.unipi.it/~luigi/netmap/

Netmap is for writing fast code in userspace. With this you get to run the code in kernel space, in a more limited environment, but which may be sufficient for many tasks.

This has quite some of the worst documentation I have ever seen, and as you can imagine, in this industry, there's strong competition.

How does this compare to DPDK?

this is seems to be an offshoot/extension of pf-ring.

apart from performing packet operations in userland also defines a language with functional-composition (take a packet, return an 'enriched' packet) for further processing e.g. fanout/io etc.

ast from pfq/lang application gets translated into appropriate structures, in the kernel, and gets executed on top of the driver...