And libev is a C wrapper around epoll and other system calls. There's not much code needed to use epoll directly, that's what John Fremlin's TPD2 web server (the previous "world's fastest Common Lisp web server") did:
What libev provides is a very portable wrapper around all the different non-blocking IO system calls in all the different Unixes. That's the hard part.
Indeed, Node.js is a thin FFI wrapper on top of lots of C (and C++) code that does all the heavy lifting, but it is still useful. I think Woo is useful the same way.
the title implies "the heavy lifting" is written in LISP.
Every node user knows the net lib nodejs uses isnt written in javascript.And most also know that in order for node to be useful,scripts should do as little as possible and delegate any serious operation to C/C++.
"built on top of libev"
The lisp part is a thin ffi wrapper on top of lots of C code.
Not than an ffi wrapper around C code isn't useful, but it's C code that does all the heavy lifting there.