YFi Hotspot Manager is a modern AJAX Web front-end for FreeRADIUS 2.x. It has support for vouchers, permanent users, billing post paid, and pre-paid. Multiple languages are supported. Statistics can be generated. It works with CoovaChilli and Mikrotik. It runs on Ubuntu and CentOS. It has Google Maps integration. Third party systems can be integrated. There is thorough documentation.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.