This is (most of) the curl.haxx.se web site contents. It mostly builds static HTML files that are preprocessed.
The web site is a on old custom made setup that mostly builds static HTML
files from a set of source files. The sources files are preprocessed with what
is basically a souped-up C preprocessor called fcpp and a set of perl
scripts. The man pages get converted to HTML with roffit. Make sure fcpp,
perl, roffit, make and curl are all in your $PATH.
Once you've cloned the git repo the first time, invoke sh bootstrap.sh once
to get a symlink and some some initial local files setup, and then you can
build the web site locally by invoking make in the source root tree.
Note that this doesn't make you a complete web site mirror, as some scripts and files are only available on the real actual site, but should give you enough to let you load most HTML pages locally.