https://docs.redhat.com/en/documentation/red_hat_fuse/7.13/html/apache_cxf_development_guide/jaxwshandlers
Chapter 43. Writing Handlers | Apache CXF Development Guide | Red Hat Fuse | 7.13 | Red Hat...
Chapter 43. Writing Handlers | Apache CXF Development Guide | Red Hat Fuse | 7.13 | Red Hat Documentation
https://manpages.ubuntu.com/manpages/xenial/man3/Plack::Handler::Apache1.3pm.html
Ubuntu Manpage: Plack::Handler::Apache1 - Apache 1.3.x mod_perl handlers to run PSGI application
Apache 1.3.x mod_perl handlers to run PSGI application