Friendica (formerly known as Friendika) is open source software that implements a distributed social network. It has an emphasis on extensive privacy settings and easy server installation. It aims to federate with as many other social networks as possible.
Why Friendica? Because somebody has to stand up for the people of the Internet. This is why we exist. Friendica is our alternative to those “creepy” social networks that don’t really care about your privacy, and only seem to care how they can profit from taking it away. They seem to be constantly making it harder for your social communications to actually reach your friends and families, and easier for unwanted people to sell you stuff.