Entel Internet provides a simple free internet service - no contracts or software to download, instead users simply need to dial the access number and enter the supplied username/password. The only charge is a per-minute local-rate phone charge (the exact rate depends on which local phone company you are using).
Terra's LIBRE plan offers unlimited free internet access across Chile - all you pay for is a local phone call. NOTE: Terra is partnered with several phone companies; you must be a customer of one of these companies (see website for list) in order to use the service since the call charges will be added to your bill.