GEOS / Development Edit this page


Developer Resources

Bug Reporting

Defects should be reported using GitHub Issues.

When submitting bugs caused by particular geometries, you must submit the geometries that cause the failure, preferably in hex-encoded WKB, so that we can re-produce the failure cases.


To contribute fixes to outstanding issues, enhancements, and other smaller changes, open a pull request with your change and a fullsome description of what you are trying to achieve.

If you have any doubts as to whether your work, or planned work, is not a “smaller” change, please join the geos-devel mailing list and describe your plans. Join the list! It is a great way to get acquainted with what the development community is working on.

Relationship to JTS

GEOS started as a direct port to C++ of the JTS Topology Suite (JTS), and remains tightly bound to that project. Most core algorithms have been prototyped in JTS and ported to GEOS when complete.

The projects attempt to share testing data, and to ascertain when failures are caused by differences in implementation (GEOS fails and JTS does not) and when they are caused by algorithm (both libraries fail).


The GEOS project is run by a Project Steering Committee made up of developers and contributors to the project and is a project of OSGeo.