Spidr is a mirror for Solar Terrestrial Data such as geomagnetic indices, ionospheric soundings, sunsport numbers etc and DMSP satellite imagery. In total each SPIDR site contains over 20 Gb of data dynamically served through a web based front end system.
	SPIDR sites are kept in synch through a JavaMail based mirror system.
	Each site is not required to host every data set. Data sets which are not mirroed are accessed remotely through the NGDC site providing data equivalent access at each site with improved access to some.
	There are currently 5 SPIDR site sup and operation with a visit by the Chinese planned for early October.
	SPIDR is designed to be server minimal, a simple site can consist of a single PC with several Gb of disk space. For sites that wish to maximize performance SPIDR offers the ability to scale to unlimited parallel servers. The master site in Boulder is currently running on 8 Linux based PC's the site in South Africa on a single PC.