A Gma"ch (an acronym for Gemilut Chasadim) is the contemporary term for a 'free-loan society'. These types of societies exist all over the Jewish world, but have become a strong part of the social landscape in Israel, especially in religious communities. It can contain almost anything - most commonly money, wedding dresses (or other fancy women's clothing), tables, and chairs. There are a few that I've heard of that really take the cake, though:
- When we lived in Alon Shvut at the beginning of the most recent intifadeh, the road between Gush Etzion and Jerusalem was often closed because of rock-throwing and shooting. Someone from the yishuv (actually, Rav Danny and Susan Wolf) opened a 'bulletproof vest and helmet' gmach, for instances when a family had to travel together to Jerusalem. We actually procured out own armor, which we donated to the gmach when we moved out of the Gush.
- Back when DVDs were a novelty, it was not yet on the radar of the Chareidi powers-that-be. Although a TV - even just a monitor - and VCR were verboten, nothing had yet been said about playing DVDs on ones computer. Thus, someone opened a video store in Kiryat Sefer, but called it a 'DVD gmach'. Very creative.
- While Ruchama was in the NICU at Hadassah-Mt. Scopus, we temporarily moved to Jerusalem to be near her. Several families in the area invited us regularly for Shabbat meals. There was one family who had a refrigerator with an automatic ice-maker. They were concerned about the fact that if one removed ice from the ice bucket, the machine would sense that the ice was running low and make more ice. To avoid issues of grama, they disabled the sensor. Problem was that the freezer began making ice non-stop. So they notified all of the neighbors, who began stopping by to pick up ice for the Shabbat meal. They called it their 'ice-gmach', which is really funny if you speak Yiddish.