The `p4est` software library enables the dynamic management of a collection of adaptive octrees, conveniently called a forest of octrees. `p4est` is designed to work in parallel and scales to hundreds of thousands, even millions, of processor cores. It is actively maintained and used by researchers worldwide.

`p4est` is free software released under the GNU General Public Licence version 2.

This website's development is tracked in a public git repository.

### Source code

Please see the github repository of `p4est` or download the latest release tarball. The source comes with commented example programs and test cases. You can also download older stable releases.

`p4est` uses `libsc` written by the same authors and others for basic helper functionality such as logging, array and hash data structures, parallel statistics, and more. `libsc` also integrates the third-party libraries `zlib` and `lua`. `libsc` is free software under the LGPL v2.1 and hosted at github.

Please note that the so-called releases auto-generated by github do not work (they are lacking the subdirectory sc and some generated files). We attach properly versioned `.tar.gz` files of our own to each release.

### Binary packages

`p4est` version 2.2 and a matching `libsc` are available in Debian testing, unstable, and buster-backports.

Contributed packages of `p4est` are available for Gentoo Linux (these are also available on the deal.ii download page) and the Homebrew distribution.

### Autogenerated API documentation

This is the doxygen output for `p4est` and for `libsc`. Recreate it with `make doxygen` after calling `configure`.

### Howto document and step-by-step examples

We have added a new recommended first example for using `p4est` with application data.

Here is a somewhat ancient howto document on the basic interface design of `p4est` including comments on the step-by-step examples included in the source code.

### Questions / Get involved

We appreciate comments, bug reports, and suggestions for adding features. To this end, we recommend using the issue tracker. We will also consider pull requests, but it might be coordinated more easily if you get in touch with us first. For further questions and suggestions, please email us at p4est@ins.uni-bonn.de. We have reconfigured this email list, so if your subscription request did not go through the first time, please try again.

### Proprietary / Commercial use

`p4est` is free software according to the Free Software Foundation. The GPL license permits any use whatsoever as long as derived works are open-sourced under the same terms. For commercial, closed-source use, such as distributing a binary executable without the source, you may double-license the software by negotating the terms with myself and UT Austin OTC.