We're going to need some way to categorise databases, so that people can search for data sets belonging to various topics.
One potential approach might be for people to tag their databases using (user created) tags, and having a site wide search (or similar) that allows for searching on them.
+1 for tags approach. It's a good way to allow a database to fall into multiple categories. You could allow for searching on one or many tags with AND/OR constraint resulting in pretty robust querying by users very easily.
Kind of suspecting (hoping) it'll be a fairly common approach. So there might be existing libraries we can use for most of the work, instead of needing to write it from scratch. Or at least look through for implementation ideas.
If not, then well... just another thing to add to the list of what needs writing. 😇