By going through the page I understood:
* Graylog2 is probably version 2 of Graylog (fair enough) * It's a data analytics platform, where you can feed your syslog. * Has a REST interface
What I would like to understand but was not able to:
* Do they open source both client and server? * Is it only a server app with a web interface? * To they sell anything at all? (support, plans, etc)