Created a list of all entities which is displayed on the left. Added the ability to select entities from that list, and made it so clicking on an already selected entity, via either the list or the field, will center the camera on that entity. Not too bad.
Next up… I think it’s time to start building the behavior display, which is what’s going to take up the top bar. This will show all the behaviors applied to the currently selected entity, and what parameters each behavior is set with. Eventually these will be editable as well, but first and foremost I’m just going to try to get it working. It will probably also display certain other information about the entity, such as its world position, name, and id number: I may start off with those, since they’re likely to be easier than the behavior display stuff, which is going to require a bunch of special-case code since behaviors vary wildly in their parameters.