Blue Spatial is an ESRI Geoservices REST Implementation. Blue Spatial is a drop in replacement for ArcGIS Server that works with all ESRI API's and ArcGIS Desktop. Blue Spatial was created as an alternative to ArcGIS Server for organizations that have existing investments / apps built with ESRI technology but would like to reduce the ongoing expense of ArcGIS Server and or ArcGIS Online. Blue Spatial can also be used by customers that want an ESRI compatible, inexpensive, lightweight and easy to use system for their spatial infrastructure. See how easy it is to setup and use by watching the screencasts.