Here is a list of all topics with brief descriptions:

[detail level 123]

Automatic and symbolic differentiation	A group dedicated to the implementation of functions and classes that relate to automatic and symbolic differentiation
deal.II and Modern C++ standards
Concepts, or expectations on template parameters
CUDA Wrappers
▼Degrees of Freedom
Constraints on degrees of freedom
Exceptions and assertions
▼Finite elements
Base classes
▼Finite element access/FEValues classes
Handling vector valued problems
Finite element space descriptions
Mappings between reference and real cell
How Mapping, FiniteElement, and FEValues work together
The interplay of UpdateFlags, Mapping, and FiniteElement in FEValues
Handling vector valued problems
Functions
The geodynamics demonstration suite
Geometric and other primitives
▼Grids and Triangulations
▼Iterators on mesh-like containers
Accessor classes of the mesh iterators
Manifold description for triangulations
Grid reordering and cell orientation	A group describing how deal.II consistently orients Triangulation objects
▼hp-finite element support
hp-Collections
▼Integrators
The MeshWorker interface
▼Input/Output
Input
Graphical output
Textual output
▼Linear algebra classes
Linear Operators
▼Matrix classes
Basic matrices
Derived matrices
Preconditioners and Relaxation Operators
▼PETScWrappers
SLEPcWrappers
Preconditioners and Relaxation Operators
SLEPcWrappers
Linear solver classes
Sparsity patterns
TrilinosWrappers
Vector memory management
Vector classes
Matrix-free infrastructure
Multilevel support
Numerical algorithms
▼Parallel computing	A group discussing the use of multiple processors
Parallel computing with multiple processors using distributed memory	A group discussing the use of parallelism on distributed memory clusters
Parallel computing with multiple processors accessing shared memory	A group discussing the use of parallelism on shared memory machines. See the detailed documentation and Table of Contents below the lengthy list of members of this group
Physics	A group dedicated to the implementation of functions and classes that relate to continuum physics, physical fields and materials
Polynomials and polynomial spaces
Quadrature formulas
Simplex support (experimental)
▼Utility functions and classes
Memory handling
Data storage primitives
TpetraWrappers
OpenCASCADE