 # Orekit > An accurate and efficient core layer for space flight dynamics applications [Orekit](https://www.orekit.org) is a low level space dynamics library written in Java. Orekit is designed to be easily used in very different contexts, from quick studies up to critical operations. As a library, Orekit provides basic elements (orbits, dates, attitude, frames, ...) and various algorithms to handle them (conversions, propagations, pointing, ...). ## Download ### Official releases [Official Orekit releases](https://gitlab.orekit.org/orekit/orekit/releases) are available on our [Gitlab instance](https://gitlab.orekit.org/). They are also available in the [Maven repository](https://mvnrepository.com/artifact/org.orekit/orekit). ### Development version To get the latest development version, please clone our official repository and checkout the `develop` branch: ```bash git clone -b develop https://gitlab.orekit.org/orekit/orekit.git ``` __Note:__ Our official repository is [mirrored on Github](https://github.com/CS-SI/Orekit). ## Documentation Project overview, architecture and development, detailed features list, tutorials, Javadoc and a lot of other information is available on the [Maven site](https://www.orekit.org/site-orekit-development/). ## Getting help The main communication channel is our [forum](https://forum.orekit.org/). You can report bugs and suggest new features in our [issues tracking system](https://gitlab.orekit.org/orekit/orekit/issues). When reporting security issues check the "This issue is confidential" box. ## Contributing Orekit exists thanks to the contribution of [many people](https://gitlab.orekit.org/orekit/orekit/graphs/develop). Please take a look at our [contributing guidelines](src/site/markdown/contributing.md) if you're interested in helping! ## Building Detailed information on how to build Orekit from source either using Maven or Eclipse is provided in [building.md](src/site/markdown/building.md) file. ## Dependencies Orekit relies on the following [FOSS](https://en.wikipedia.org/wiki/Free_and_open-source_software) libraries, all released under business friendly FOSS licenses. ### Compile-time/run-time dependencies * [Hipparchus](https://hipparchus.org/), a mathematics library released under the Apache License, version 2.0. ### Test-time dependencies * [JUnit 4](http://www.junit.org/), a widely used unit test framework released under the Eclipse Public License, version 1.0. * [Mockito](https://site.mockito.org/), a mocking framework for unit tests, released under MIT license. More detailed information is available in the [Maven site](https://www.orekit.org/site-orekit-development/dependencies.html). ## License Orekit is licensed by [CS Systèmes d'Information](https://www.c-s.fr/) under the [Apache License, version 2.0](http://www.apache.org/licenses/LICENSE-2.0.html). A copy of this license is provided in the [LICENSE.txt](LICENSE.txt) file.