This is the hypertext version of the USIGS Technical Architecture - Revision A, dated 26 January 1999. The paper copy of the USIGS Technical Architecture remains the official version. This hypertext version was developed to make the USIGS Technical Architecture immediately accessible to all who wish to use it in a speedy, nonlinear manner. No substantive changes whatever were made to the paper copy of the NCCB approved USIGS Technical Architecture.