A simple static file server add xpi file support. From https://www.acmesystems.it/python_http .

static_file_server.py

from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer
from os import curdir, sep

PORT_NUMBER = 8080

#This class will handles any incoming request from
#the browser
class myHandler(BaseHTTPRequestHandler):

    #Handler for the GET requests
    def do_GET(self):
        if self.path=="/":
            self.path="/index_example2.html"

        try:
            #Check the file extension required and
            #set the right mime type

            sendReply = False
            if self.path.endswith(".html"):
                mimetype='text/html'
                sendReply = True
            if self.path.endswith(".jpg"):
                mimetype='image/jpg'
                sendReply = True
            if self.path.endswith(".gif"):
                mimetype='image/gif'
                sendReply = True
            if self.path.endswith(".js"):
                mimetype='application/javascript'
                sendReply = True
            if self.path.endswith(".css"):
                mimetype='text/css'
                sendReply = True
            if self.path.endswith(".xpi"):
                mimetype='application/x-xpinstall'
                sendReply = True

            if sendReply == True:
                #Open the static file requested and send it
                f = open(curdir + sep + self.path)
                self.send_response(200)
                self.send_header('Content-type',mimetype)
                self.end_headers()
                self.wfile.write(f.read())
                f.close()
            return


        except IOError:
            self.send_error(404,'File Not Found: %s' % self.path)

try:
    #Create a web server and define the handler to manage the
    #incoming request
    server = HTTPServer(('', PORT_NUMBER), myHandler)
    print 'Started httpserver on port ' , PORT_NUMBER

    #Wait forever for incoming htto requests
    server.serve_forever()

except KeyboardInterrupt:
    print '^C received, shutting down the web server'
    server.socket.close()