pro or free

Pro bono publico (English: "for the public good"; usually shortened to pro bono) is a Latin phrase for professional work undertaken voluntarily and without payment. Unlike traditional volunteering, it uses the specific skills of professionals to provide services to those who are unable to afford them.
Pro bono publico is also used in the United Kingdom to describe the central motivation of large organizations, such as the National Health Service and various NGOs which exist "for the public good" rather than for shareholder profit, but it equally or even more applies to the private sector where professionals like lawyers and bankers offer their specialist skills for the benefit of the community or NGOs.

View More On Wikipedia.org