Nxt is an open source cryptocurrency and payment network launched in November 2013 by anonymous software developer BCNext. It uses proof-of-stake to reach consensus for transactions - as such there is a static money supply and no mining as with Bitcoin.
Nxt is specifically conceived as flexible platform to build applications and financial services around. It has an integrated asset-exchange (comparable to shares), messaging system and marketplace. Users can also create new currencies within the system.
The last major release enabled Multisignature capabilities and a plugin-system for the client.
On 28 September 2013 Bitcointalk member BCNext created a forum thread announcing Nxt as second generation cryptocurrency, asking for small Bitcoin donations to determine how to distribute the initial stake. On 18 November 2013 fundraising for Nxt was closed, with 21 BTC raised. The genesis block was published on 24 November 2013.
It revealed that 1,000,000,000 coins had been distributed to 73 stakeholders in proportion to their level of contribution. The source code was partially released on 3 January. The full source code was released on 1 March 2014 under the MIT License.