:Author: OSGeo-Live
:Author: Frank Warmerdam
:Reviewer: Cameron Shorter, LISAsoft
:Version: osgeo-live6.0
:License: Creative Commons Attribution 3.0 Unported (CC BY 3.0)

.. image:: ../../images/project_logos/logo-GEOS.png
  :alt: project logo
  :align: right
  :target: http://geos.osgeo.org/

.. image:: ../../images/logos/OSGeo_project.png
  :scale: 100
  :alt: OSGeo Project
  :align: right
  :target: http://www.osgeo.org/incubator/process/principles.html

GEOS
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Spatial Library
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GEOS (Geometry Engine - Open Source) is a C++ port of the `JTS Topology Suite (JTS) <http://tsusiatsoftware.net/jts/main.html>`_. It includes the OpenGIS Simple Features for SQL spatial predicate functions and spatial operators, as well as specific JTS enhanced topology functions.

GEOS is the most widely used geospatial C++ geometry library, being used by open source projects such as :doc:`PostGIS <postgis_overview>`, :doc:`QGIS <qgis_overview>`, :doc:`GDAL/OGR <gdal_overview>` and :doc:`MapServer <mapserver_overview>`, and by proprietary products including `FME <http://www.safe.com/fme/fme-technology/>`_.

Implemented Standards
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* `OpenGIS Simple Features for SQL <http://www.opengeospatial.org/standards/sfs>`_  spatial predicate functions and spatial operators

Core Features
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* Geometries: Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, GeometryCollection
* Predicates: Intersects, Touches, Disjoint, Crosses, Within, Contains, Overlaps, Equals, Covers
* Operations: Union, Distance, Intersection, Symmetric Difference, Convex Hull, Envelope, Buffer, Simplify, Polygon Assembly, Valid, Area, Length, 
* Prepared geometries (pre-spatially indexed)
* STR spatial index
* OGC Well Known Text (WKT) and Well Known Binary (WKB) encoders and decoders.
* C and C++ API (C API gives long term ABI stability)
* Thread safe (using the reentrant API)

Details
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**Website:**  http://geos.osgeo.org/

**Licence:** LGPL

**Supported Platforms:** Windows, Linux, Mac

**API Interfaces:** C, C++

**Support:** http://lists.osgeo.org/mailman/listinfo/geos-devel, http://www.osgeo.org/search_profile