Some computer programs I developed, see [1] and [2] for details.

widmo - 6.5.0

Evaluation of the Selberg zeta function for Gamma_0(n) with (non-arithmetic) character, computation of the spectrum of the transfer operator for Gamma_0(n) with character

cgf - 2.3.1

Symmetries of the transfer operator for Gamma_0(n) with character, calculation of Hecke operators for period functions, Fricke operators for period functions and period functions for Gamma_0(n), some examples

[1] Character deformation of the Selberg zeta function for congruence subgroups via the transfer operator; M. Fraczek, Ph.D. Thesis (2012), PDF

[2] Spezielle Eigenfunktionen des Transfer-Operators für Hecke Kongruenz Untergruppen; M. Fraczek, Diploma-Thesis, (2006), PDF