A server-side solution is more compatible, until the "download" attribute is implemented in all the browsers.
One Python example could be a custom HTTP request handler for a filestore. The links that point to the filestore are generated like this:
http://www.myfilestore.com/filestore/13/130787e71/download_as/desiredName.pdf
Here is the code:
class HTTPFilestoreHandler(SimpleHTTPRequestHandler):
    def __init__(self, fs_path, *args):
        self.fs_path = fs_path                          # Filestore path
        SimpleHTTPRequestHandler.__init__(self, *args)
    def send_head(self):
        # Overwrite SimpleHTTPRequestHandler.send_head to force download name
        path = self.path
        get_index = (path == '/')
        self.log_message("path: %s" % path)
        if '/download_as/' in path:
            p_parts = path.split('/download_as/')
            assert len(p_parts) == 2, 'Bad download link:' + path
            path, download_as = p_parts
        path = self.translate_path(path )
        f = None
        if os.path.isdir(path):
            if not self.path.endswith('/'):
                # Redirect browser - doing basically what Apache does
                self.send_response(301)
                self.send_header("Location", self.path + "/")
                self.end_headers()
                return None
            else:
                return self.list_directory(path)
        ctype = self.guess_type(path)
        try:
            f = open(path, 'rb')
        except IOError:
            self.send_error(404, "File not found")
            return None
        self.send_response(200)
        self.send_header("Content-type", ctype)
        fs = os.fstat(f.fileno())
        self.send_header("Expires", '0')
        self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
        self.send_header("Cache-Control", 'must-revalidate, post-check=0, pre-check=0')
        self.send_header("Content-Transfer-Encoding", 'binary')
        if download_as:
            self.send_header("Content-Disposition", 'attachment; filename="%s"' % download_as)
        self.send_header("Content-Length", str(fs[6]))
        self.send_header("Connection", 'close')
        self.end_headers()
        return f
class HTTPFilestoreServer:
    def __init__(self, fs_path, server_address):
        def handler(*args):
            newHandler = HTTPFilestoreHandler(fs_path, *args)
            newHandler.protocol_version = "HTTP/1.0"
        self.server = BaseHTTPServer.HTTPServer(server_address, handler)
    def serve_forever(self, *args):
        self.server.serve_forever(*args)
def start_server(fs_path, ip_address, port):
    server_address = (ip_address, port)
    httpd = HTTPFilestoreServer(fs_path, server_address)
    sa = httpd.server.socket.getsockname()
    print "Serving HTTP on", sa[0], "port", sa[1], "..."
    httpd.serve_forever()