@Amitie_10g is interested in running a webservice on Toolforge using HHVM. It may be possible to do this with enough hacking of a tool's $HOME/.lighttpd.conf or webservice generic, but it would be much nicer for us to just add direct support in webservice and the Kubernetes containers.
In WMF production, HHVM runs in fcgi mode behind Apache2 web servers. The Tool Labs equivalent would use Lighttpd instead of Apache2. It is also possible to run HHVM in proxygen mode which is advertised as providing a full web server.