Where does launchpad store folder information? (database, etc?)
Ok, I think i've found it. Turns out that (at least under El Capitan) things are a little different.

This AskDifferent answer by Greg Hacke pointed me in the right direction.

It seems the databases are stored in $TMPDIR/../0/com.apple.dock.launchpad/db/, with the main sqlite db being aptly named db.

(After reading Geoff Hackworth's AskDifferent response, it seems a better way to get the path would be getconf DARWIN_USER_DIR rather than $TMPDIR/../0/)

Editing this with a sqlite GUI showed that the groups table stores the folders, with title holding the folder name.

After making any desired changes, and writing them back to the db, we still need to do a killall Dock to refresh the launchpad screen.

Some observations:


There are a number of groups that don't have a title (set to null), so not really sure what they are for.
It seems that just creating a new entry doesn't cause a group to show up (maybe because it would be an 'empty folder'?).


In this case, how can we create a new folder and move apps into it from the db?

By editing the title field in the apps table we can change the display name of the app.