The PyPSA preprint paper contains a discussion of PyPSA's features compared to other software tools and a functionality comparison in Table III.
PYPOWER - a Python, numpy, scipy port of MATPOWER, compared to PyPSA below
pandapower - a Python based extension of PYPOWER that uses pandas "to create an easy to use network calculation program aimed at automation of power system analysis and optimization in distribution and sub-transmission networks"
GridCal - a Python-based extension of PYPOWER that includes time series and load flow methods using analytic continuation
MATPOWER - a Matlab-based tool for static power system computations
PSAT - a general Matlab-based tool for (most) power system calculations
Open Energy Modelling Framework - Python and Pyomo based framework for optimisation which includes all energy sectors in a general framework
Calliope - Python and Pyomo based framework for energy system optimisation
OSeMOSYS - systems optimization model for long-run energy planning
vSPD - Vectorised Scheduling, Pricing and Dispatch (vSPD) - an audited, mathematical replica of SPD, the pricing and dispatch engine used in the New Zealand electricity market.
PyPSA is compared to PYPOWER in the following table:
PSS/E
Neplan
PowerWorld
INTEGRAL