Web server capable of directory index with parallel requests handling and white spaces filenames support

I was searching for simple web server that is capable to directory index. In the past I was using python -m SimpleHTTPServer drawback of this is solution is that it only can serve one request at time. Then I inspired by following question What is a faster alternative to Python's SimpleHTTPServer? and I've tried node.js and twisted. Those two solved the problem with processing one request at time but another problem here is that both node.js and twisted are not able to process files which contains spaces (python solution worked). How to have both parallel requests handling and support for white spaces in filenames?