CLAM is the name of a virtual currency. The individual coins are known as CLAMs, while some might refer to it as clam coin. The idea behind CLAMs is that distribution is made as fair as it can possibly be. You will need to dig up CLAMs to obtain them, but some people have discovered they already have some, even though they didn’t previously realize it. That might sound odd, but if you had a BTC wallet prior to May 12th, 2014, and the wallet had a balance, you might own CLAMs too. The same applies if you had a DOGE address or an LTC address.
The original software that led to the development of Bitcoin has been used for many other cryptocurrencies since created. This applies to CLAM as well. Since the original software is open source, it has proven useful for others who wanted to create their own cryptocurrencies.