Free Software
Large number of open source computational chemistry codes are available . Many of them are simple to compile and use even on a laptop. Here are some of the computational chemistry codes that I use for my research-
NWChem (https://github.com/nwchemgit/nwchem)
OpenMolcas (https://gitlab.com/Molcas/OpenMolcas)
Orca (https://orcaforum.kofo.mpg.de/app.php/dlext/)
DFTB+ (https://dftbplus.org/)
Dalton (https://daltonprogram.org/)
Gamess (https://www.msg.chem.iastate.edu/gamess/)