Gemach (Hebrew: גמ"ח, plural, גמחים, gemachim, an abbreviation for גמילות חסדים, gemilut chasadim, "acts of kindness") is a Jewish free-loan fund that subscribes to both the positive Torah commandment of lending money and the Torah prohibition against charging interest on a personal loan to a fellow Jew. Unlike bank loans, gemach loans are interest-free, and are often set up with easy repayment terms.
Gemachs operate in most Jewish communities. The traditional gemach concept — that of a money-lending fund — extends loans on a short- or long-term basis for any need, including emergency loans, medical expenses, wedding expenses, etc. However, many people have expanded the concept of gemachs to include free loans of household items, clothing, books, equipment, services and advice.
Gemachs may be operated both on a communal basis (such as by treasurers of community funds) and an internal basis (such as by businesses, organizations, schools and families). The ideal of contributing to or forming one's own gemach was popularized by Rabbi Yisrael Meir Kagan (the Chofetz Chaim), who addressed many halachic questions about the practice and lauded its spiritual benefits in his landmark book, Ahavat Chesed ("Loving Kindness").