Best community websites built with Discourse

Because its a good piece of software but for starting a free community you have to pay minimal 100 bugs for this software maybe this a (to hard step in) when you make ex. a gaming community with your private money.

For companys it maybe not. Why not use slack instead ?

Can I really use Slack to build an actual community? How can that be done? Not sure what you meant by that. Please explain, thanks!

See Sitepoint's community at http://community.sitepoint.com/

The last one I noticed was http://www.Growthtalk.co - which you already know..