nghttp2 v0.4.1 just released today. It is mainly a bug fix release.
The supported HTTP/2 protocol version remains
Although this release is tagged as bug fix release, nghttpx got some
--npn-list option now works with ALPN.
* is officially allowed as
<HOST> parameter in
--frontend option and it means wildcard address, which can bind to
both IPv4 and IPv6 addresses.