Steemit!

Diaspora is a federated social networking service, designed to be a more privacy-aware alternative to Facebook . Share what you want, with whom you want.

Stack Exchange is a fast-growing network of 84 [and counting] question and answer sites on diverse topics from software programming to cooking to photography and gaming. We are an expert knowledge exchange: a place where physics researchers can ask each other about quantum entanglement, computer programmers can ask about JavaScript date formats, and photographers can share knowledge about taking great pictures in the snow.

Quora.com is a question/answer service allowing users to pose questions that other users can answer, each question and answer can have comments, each users can write one individual answer and there can be a summary answer.Each user can choose a description explaining their area of expertise or questions and answers can be anonymous.Questions and answers are searchable.

Hacker News is a social news website that caters to programmers and entrepreneurs, delivering content related to computer science and entrepreneurship.

Friendica is a distributed social network application which runs on commodity hosting platforms - PHP/MySQL/Apache. (If you can install Drupal or Wordpress you can probably install Friendica)

Flattr is a social micropayment service, that makes it easy for you to "flatter" things on the internet that you like. When you're registered to Flattr, you pay a small monthly fee of your own choosing. At the end of the month, that fee is divided between all the things you flattered. You can even flatter things in the real world, with the Flattr Android app!

Hubzilla is a powerful platform for creating interconnected based websites featuring a decentralized identity, communications, and permissions framework built using common webserver technology. Hubzilla is very suitable for communities (of any size).

Litecoin is a peer-to-peer Internet currency that enables instant payments to anyone in the world. It differs from its parent Bitcoin in that can be efficiently mined with consumer-grade hardware. Litecoin provides faster confirmations (targeted at every 2.5 minutes on average) and uses memory-hard, scrypt-based mining to target the CPUs and GPUs most people already have. The Litecoin network is scheduled to produce four times as many currency units as Bitcoin.

Dogecoin is an open source, decentralized, peer-to-peer cryptocurrency, favored by Shiba Inus worldwide.