FFCx is a new version of the FEniCS Form Compiler. It is being
actively developed and is compatible with DOLFINx.

FFCx is a compiler for finite element variational forms. From a
high-level description of the form in the Unified Form Language
(UFL), it generates efficient low-level C code that can be used to
assemble the corresponding discrete operator (tensor). In particular,
a bilinear form may be assembled into a matrix and a linear form may
be assembled into a vector. FFCx may be used either from the command
line (by invoking the ffcx command) or as a Python module.