Litecoin LTC

Launched in 2011 as a lighter copy of Bitcoin: Charlie Lee took the same code and changed the parameters — a block every two and a half minutes instead of ten, a cap of 84 million coins instead of 21 million, Scrypt mining instead of SHA-256. The intent was faster payment confirmation and mining that stayed within reach of ordinary hardware for longer.

The network has run without interruption longer than almost any other and has spent decades as a proving ground: several protocol changes were tested here before reaching Bitcoin. The block reward halves on the same principle but on its own schedule, and an optional extension was added later that lets amounts and addresses be concealed.

In practice its use comes down to transfers and settlement between trading venues: an application ecosystem of its own never took shape here. Several protocol changes later adopted by Bitcoin were switched on in this network first.

That optional privacy extension prompted some regulated venues to delist the coin, even though transfers remain transparent by default.