Version 3.0 of the deal.II object-oriented finite element library is available on the deal.II home-page at

deal.II is a C++ program library targeted at adaptive finite elements and error estimation. It uses state-of-the-art programming techniques of the C++ programming language to offer you a modern interface to the complex data structures and algorithms required for adaptivity and enables you to use a variety of finite elements in one, two, and three space dimensions, as well as support for time-dependent problems.

The library is written for research purposes and offers many features:

Support for one, two, and three space dimensions, using a unified interface that enables writing programs almost dimension independent.
Handling of locally refined grids, including different adaptive refinement strategies based on local error indicators and error estimators.
Support for a variety of finite elements, including Lagrange elements of order one through four, and discontinuous elements.
Extensive documentation: all documentation is available online in a logical tree structure to allow fast access to the information you need. If printed it comprises about 200 pages of tutorials, several reports, and far more than 1,000 pages of programming interface documentation with explanations of all classes, functions, and variables.
Modern software techniques that make access to the complex data structures and algorithms as transparent as possible. The use of object oriented programming allows for program structures similar to the structures in mathematical analysis.
Fast algorithms that enable you to solve problems with up to several millions of degrees of freedom quickly. As opposed to programming symbolic algebra packages the penalty for readability is low.
Support for several output formats, including some common formats for visualization of scientific data.
Support for a variety of computer platforms, including multi- processor machines.
Free source code under an Open Source license, and the invitation to contribute to further development of the library.

Wolfgang Bangerth, Guido Kanschat, the deal.II team