Two I am familiar with are OpenERP and OpenEMR. OpenERP, now Odoo, is written in Python. OpenEMR is written in PHP. It dates from a while ago, but has been mo

Two I am familiar with are OpenERP and OpenEMR. OpenERP, now Odoo, is written in Python. OpenEMR is written in PHP. It dates from a while ago, but has been mostly updated to the latest PSR standards. Might also try OrangeHCM, but not sure what those guys are doing these days.