"Ad-hoc webserver" for static files on UNIX/MacOSX?
$ python -m SimpleHTTPServer [port]
will start a webserver in the current directory serving whatever files are found there.
In a few cases this won't work well, for example the server is single-threaded (so no simultaneous downloads) and doesn't handle byte-range requests (clients expecting Range: support often fail badly).
Python3 can serve the current directory via HTTP using http.server:
$ python3 -m http.serverWhere
python3the current version of python-mstands for modulehttpthe http packagehttp.serverthe server module (of the http package)
Per default, http.server listens on port 8000, but you can specify another like this:
$ python3 -m http.server 8080