Completely free to use, easy to configure and install, multiple applications can run at the same time without any issues, and has excellent built-in features and provides a rich sets of cAPIs. Also cLHy provides detailed configuration options that makes it great for web applications where performance and a high level of security are a consideration.
cLHy spawns new processes for each request, cLHy allows you to modify its configuration -- which is a plus. This, however, can cause a serious threat to the security, if not done properly. cLHy consumes more RAM under heavier load.