In its current state the library is unfortunately not available to the public. Originally, it has been a plain C-library, and now gradually evolves against C++, using template meta-programming techniques to define abstract and at the same time efficient interfaces. Full support is currently limited to domain defined by piece-wise linear level-set functions, including unfitted narrow bands. There is limited support for piece-wise quadratic level-set functions in 2d, with planned full support in 2d and 3d. unfem++ was used as back-end in the numerical experiments performed for the publications on h-narrow band methods and on general aspects of unfitted finite element methods. Is is also used in ongoing research projects for free surface flows.