GIS for the Internet.

Internet GIS, which focuses on the Internet technology and utilizes a distributed architecture framework, symbolizes and invisible revolution of GIS - from closed, centralized GIS to open, distributed GIS Services. Internet GIS is an exciting research and application direction. It has been widely accepted in governmental agencies and educational institutions and among GeoSpatial data producers and users, GIS vendors, and GIS professionals.

The tremendous growth in Internet use has resulted in an increased demand for the delivery of geographic data, maps, and applications over the Internet.

ArcIMS lets you centrally build and deliver maps, data, and tools over the Internet.

ArcIMS uses XML for its communications and interactions. The openly published XML language for ArcIMS is named ArcXML. It provides access to all ArcIMS functions and capabilities. All client requests and server responses in ArcIMS are coded in ArcXML.

ArcIMS plays a key role by supporting many Web Services protocols for IT and GIS. It is important that GIS users can offer interoperability choices to their users via various specifications including XML, SOAP, WMS, WFS, GML, Z39.50, and so on. ArcIMS supports most GIS and IT Web Services standards.

Many ArcIMS developers program Web applications using ArcXML to customize and extend core ArcIMS capabilities. This is possible by using connectors.

Connectors provide communication pipeline between a Web server or third-party application server and the ArcIMS Application Server. ArcIMS has five connectors:

Gateway that facilitates managing GeoSpatial data in a DBMS.

As Database Management System (DBMS) capability has evolved into more powerful technology that could support complex data objects, large queries, and stronger transaction support, the use of DBMS for geographic data management has become much more practical. Most multi-user GIS systems today manage their data in a DBMS, and many smaller sites are beginning their migration to a DBMS.

As with other information resources in an organization, GIS data can benefit from DBMS use. In makes good sense to manage your GIS resources in a relational database. Some of the reasons to use relational databases are as valid for GIS as they are for other information systems:

• A single data store for attribute and spatial data
• Base relational model (so GIS is compliant with other information technology (IT) system requirements)
• Concurrency management in a multi-user environment
• Standard data management practices, such as backup, recovery, and replication
• Performance for any number of users
• The need for managed and organized data
• Scalable data volumes with no size limitations
• Centralized systemwide or companywide access to the data
• Data maintenance over long periods, spanning personnel changes and hardware and software upgrades
• System failure and recovery mechanisms
• Industry-standard client/server and Internet architectures (e.g. Web Services)

ArcSDE software allows you to store, use, and manage all your GIS data (including feature geometry) in commercial DBMSs such as MS SQL Server and Oracle.

ArcSDE manages the physical storage of geometry for features using standard data types provided by the host DMBS. Some DBMSs have spatial data types, while others provide standard binary or BLOB storage types: