Orekit (ORbit Extrapolation KIT) is a free java library
providing basic space dynamics objects and services.

It is licensed by CS Systèmes d'Information under the
Apache License Version 2.0. A copy of this license is
provided in the LICENSE.txt file.

The BUILDING.txt file explains how the library can be built from sources.

The src/main/java directory contains the library sources.
The src/main/resources directory contains the library data.
The src/test/java directory contains the tests sources.
The src/test/resources directory contains the tests data.
The src/tutorials/java directory contains sources for example use of the library.
The src/tutorials/resources directory contains example data.
The src/design directory contains pieces for a UML model of the library.

Orekit relies on the following free software, all released under
business friendly free licenses.

compile-time/run-time dependency:

  - Apache Commons Math from the Apache Software Foundation
    http://commons.apache.org/math/
    released under the Apache license, version 2

test-time dependency:

  - JUnit 4 from Erich Gamma and Kent Beck
    http://www.junit.org/
    released under the Common Public License Version 1.0