- Perform non-intrusive reliability analysis or Bayesian updating either
    - by expressing problems directly in Fesslix
    - by means of an Octave/Matlab interface
    - by means of a Python interface
    - by linking external applications/libraries to Fesslix
        - through a C++ or Fortran interface
        - through running commands on the command line
- Flexible input language for writing Fesslix parameter files
    - control flow statements (e.g. if, for, while)
    - most parameters can be defined as functions
- Extensible by means of modules
    - examples of modules available by default:
        - Linear finite element analysis using truss, beam and plane stress/strain elements
        - Bayesian networks
        - Working with response surfaces
        - Spectral Stochastic Finite Elements
    - users can write their own modules
- You can use Fesslix as a library and embed it in your own software