What is MetaFilter?
Weblog that anyone can contribute a link or comment to. A typical weblog is one person posting their thoughts on the unique things they find on the web. This website exists to break down the barriers between people, to extend a weblog beyond just one person, and to foster discussion among its members
Comments and Reviews
Said about MetaFilter as an alternative
Reddit was based on Metafilter, and has most of its functions - as well as an active moderation team.