Yes. Tags are the smallest unit of this website. They are used as mere keywords, but also as a tool to structure content, to mark a group of projects that have something in common, like a technology or a certain thematic context.
Just enter a url like http://www.meso.net/php (where “php” is the tag) and you’ll get an automatic view of all projects done with php. Nobody programmed this view, it’s generated completely automatically, so we call it the autoview of a tag.