deal.II — an open source finite element library

What it is: A C++ software library supporting the creation of finite element codes and an open community of users and developers. (Learn more.)

Mission: To provide well-documented tools to build finite element codes for a broad variety of PDEs, from laptops to supercomputers.

Vision: To create an open, inclusive, participatory community providing users and developers with a state-of-the-art, comprehensive software library that constitutes the go-to solution for all finite element problems.

deal.II is open source and available for free!
There are many resources for learning deal.II and asking for help.
deal.II is a community project. We welcome all who want to participate!


2017/06/17: deal.II is now part of the SPEC CPU 2017 benchmark
A program based on the deal.II library is part of the new industry standard SPEC CPU 2017 benchmark testsuite that is used to determine the speed of computers. It is part of the floating point testsuite as 510.parest.

The inclusion of our software into an industry standard benchmark testsuite will lead to better support of compilers and machines for the kind of program we write, in particular for unstructured hierarchical mesh computations. This will in turn help make our codes run faster on future systems.

2017/04/06: Version 8.5.0 released
deal.II version 8.5.0 was released today. A full list of changes can be found here and a long description of changes is in the manuscript here. Download links are on the download page, or the release page on github.
2017/01/17: step-57 - stationary Navier-Stokes equations
The new tutorial program step-57 (contributed by Liang Zhao and Timo Heister) shows how to solve the stationary, incompressible Navier-Stokes equations using Newton's method. The program features block linear solvers for the saddle point problem and adaptive mesh refinement. The benchmark problem is the famous lid-driven cavity test.
2016/07/05: step-55 and step-56 discuss options for advanced Stokes solvers
The new tutorial programs step-55 (contributed by Timo Heister) and step-56 (contributed by Ryan Grove) show how the existing Stokes solver in step-22 can be extended in parallel and using geometric multigrid, respectively. step-55 therefore fills a hole in demonstrating parallel computing at a complexity level between step-40 (the Laplace equation) and step-32 (the much more complex Boussinesq problem). step-56 extends the simple multigrid solver in step-16 to a vector-valued problem.
2016/04/14: Results of the deal.II user survey available
Earlier this year, we asked our users for feedback about deal.II in a user survey. The results of this survey are now available in this summary of responses.
2016/03/15: Version 8.4.0 released
deal.II version 8.4.0 was released today. A full list of changes can be found here. Download links are on the download page, or the release page on github.

(older news)


The primary means of communicating with deal.II developers and users is by email:

The deal.II discussion group is used by developers to announce new features and by users to ask questions about how to do things with deal.II. This is also the forum to post bug reports.

The development of the library is done on the deal.II project using Issues and Pull-Requests.

You can send an email to the project administrators Wolfgang Bangerth, Guido Kanschat, Timo Heister, and Matthias Maier if necessary.

We appreciate comments and suggestions on deal.II. They can be addressed to either of the addresses above, depending on their public or private nature.

Legal Notice: Some countries' laws require us to post this legal notice. Please write to the responsible federal judges if you find this silly.