Useful information

Components of FEniCS

Throughout the conference, you heard people refer to the different packages that make up FEniCS. For useful reference, these components are:


DOLFIN is a C++/Python finite element library, and is the main component that most users interact with.


FFC (the FEniCS Form Compiler) is a library that generates C++ code that can be used in assembly.


FIAT (the FInite element Automatic Tabulator) contains the definitions of finite element spaces, and can evaluate basis functions.


UFL (Unified Form Language) is the language in which forms can be written. These can then be interpreted by FFC and used to generate code.

Components of FEniCSx

FEniCSx is the new version of FEniCS that is currently actively developed. New features in DOLFINx include:

For useful reference, the components of FEniCSx are:


DOLFINx is the new version of DOLFIN.


FFCx (the FEniCSx Form Compiler) is the new version of FFC.


Basix is FEniCSx's new element tabulator.


(see above)

Communication channels and Q&A

There are a few ways that developers and users of FEniCS communicate online.


The FEniCS Slack channel is used for chat and discussions between developers and users. You might like to use this channel to follow up on discussions started at FEniCS 2021. To sign up for the slack channel, register your email here.


Questions about usage of FEniCS can be posted on the FEnics Discourse group.

GitHub issue tracker

Bugs and errors in FEniCSx are posted on the GitHub issue tracker.

Q&A forum (deprecated)

Before moving to Discourse, the FEniCS Q&A forum was used for asking questions about usage. New questions cannot be posted, but some users may find the archives helpful.

Useful links

The DOLFINx tutorial is an interactive guide to the features of FEniCSx. The tutorial uses Jupyter notebooks (hosted with Binder) that can be run online without any installation required.

DefElement is an encyclopedia of finite element definitions. It contains information about common (and less common) finite element basis functions are defined.