The Ardtweeno system is a distributed sensor mesh network gateway, which bridges devices connected through a serial link to devices over Internet Protocol (IP). The core system is a Ruby application with an exposed Sinatra micro web application acting as an API. It has been designed to run on the Raspberry Pi as a Platform as a Service or PaaS. Initially, Ardtweeno is designed to only store data on a MongoDB server, I may look into supporting SQL databases at a later date. If a MongoDB is not available, Ardtweeno will store data in RAM which is accessible through the API but lost if the host reboots or the gateway application shuts down.
The space that I currently see Ardtweeno occupying is a platform as a service on top of which developers can produce home automation systems, very much like a locally running version of Xively or perhaps Nimbits. Ardtweeno has the ability to receive packets of information, then store them for later analysis and graphing much like these propriety systems mentioned.
See the following wikipage for installation instructions installation
See the following wikipage for configuration instructions for configuration of the XBEE Radios configuration
See the following link to access URIs related to Ardtweeno links