You can read all about it here: http://writeoncon.com/about/what-is-writeoncon/
The main point is that its an online conference to support writers. It focusses mainly on kidlit, however, the information would benefit all.
I've never been before. I found the website due to a link to a competition where Ginger Clark of Curtis Brown is offering to do a free critique.
There are lots of other competition being run too, with the most recent being a chance to recieve a critique on your query letter.