SharePoint 2013 we have the new "Community Site". Top create one simply access the "Site Contents" link and then select the link to create a new sub site and choose the community site.
Once it has been created you should get something that looks like this:
As you can see there are great features right here on the home page. The middle of the site contains the aggregation of things that are important to the community site.
New discussions can be created very easily by select the link and completing the following details. Notice the new option "I am asking a question and want to get answers from other members".
Once it is added it renders on the home page with other details and easy to click link to get access to the body of the discussion.
Inline reply can be achieve by accessing the discussion item and then adding your reply using the web part underneath the discussion item.
As an administrator on the right if the actual discussion I can perform the following actions:
Selecting to manage the discussion takes you directly to the hosting list of the discussion where you can see the full details of the item. Plus you also get to use the ribbon bar feature to designate a featured discussion.
You can create categories by using the second link, more importantly you can assign badges to members.
Once set this then adds the simple tag to the user in the site.
Setting the reputation settings allows for you to set what the thresholds are for the users reputation score.
On this page you can also manage the badges that are assigned to the users.
Some base settings can be updated using "Community Settings".
With all the settings for reputation completed you are then able to see the following about the members of the site.