Yes, those alternate root nameservers are the ones from Open Root Server Confederation, or ORSC.

There has been a lot of controversy regarding TLD assignment as performed by ICANN and other institutions, and ORSC was started in 1997 to help alleviate some of the problems — mainly, TLDs are assigned on FCFS basis, and there are no political or any other motives that influence TLD assignment.

In short, it means fair assignment to all interested parties. If you care about freedom and openness of Internet, open root nameservers are the way to go. Read all about how to set your system up for using them at ORSC support page.

For those that don't know, "root nameservers" are also "metanameservers" — nameservers that provide addresses (or "serve names") for other nameservers, which actually provide names for real domain names ;-)