121 Sensor Web is a revolutionary concept of achieving a collaborative, coherent, consistent, and consolidated sensor data collection, fusion and distribution system. Sensor Webs can perform as an extensive monitoring and sensing system that provides timely, comprehensive, continuous and multi-modeobservations. This new earth observation system opens up a new avenue to fast assimilation of data from varioussensors (both in situ and remote) and to accurate analysis and informed decision making. One of the drivingforces is the Sensor Web Enablement (SWE) Initiative by the Open Geospatial Consortium. Since it started itswork in 2001, the SWE working group has developed specifications which are now in the final stages of becoming OGC specifications. The Sensor Web Group of the free and open source software initiative 52°North is directly involved in the specification process and provides the complete suite of OGC SWE services, encodings,clients and sensor web specific data rendering engines. This presentation addresses the Sensor Web Enablement (SWE) process by the Open Geospatial Consortium (OGC) and its implementation as free and open source software. We will show the latest developments in the standardization process and how the different SWE services and encodings integrate in mainstream web-based geospatial solutions like web map or catalogue services. The work is driven and coordinated by the open source initiative 52°North (http://www.52north.org), which works in close cooperation with the Sensor Web Alliance (http://www.sensorweb-alliance.org) and the Meraka Institute of the Council for Scientific and Industrial Research (South Africa). FOSS4G2006 - Free And Open Source Software for Geoinformatics Session 2 : SDI-OGC-Security Ingo Simonis ingo.simonis@googlemail.com Andreas Wytzisk wytzisk@itc.nl Johannes Echterhoff echterhoff@uni-muenster.de Johannes Echterhoff echterhoff@uni-muenster.de <MaKaC.conference.ContributionType object at 0xb35da42c> OGC