Please see the announcement about the forum migration. phpBB belongs in a museum I'm afraid...
New posts are highlighted as KuriKai says and posts with new comments have a bright "new" badge on them. I've set the recent discussions page as the default page so it's easy to see what's new.
Also, if you go to your user profile, you can set up a variety of notifications (email or just a notification popup) of the categories and types of messages you're interested in.
The mobile theme is currently a bit unfinished, but it also highlights new posts.
I made a couple of style tweaks to further make it clear what is unread (orange bar on the left side of the discussion item, darker background). Also, I added another bar on the right edge to indicate discussions you have participated in.
Comments
Also the categories/discussions are bolded when there are new posts
New posts are highlighted as KuriKai says and posts with new comments have a bright "new" badge on them. I've set the recent discussions page as the default page so it's easy to see what's new.
Also, if you go to your user profile, you can set up a variety of notifications (email or just a notification popup) of the categories and types of messages you're interested in.
The mobile theme is currently a bit unfinished, but it also highlights new posts.