Show content/template for the /tag/ or /taxonomy/ part of the URL in WordPress

Heu,

I’ve been trying to figure this problem out but can’t quite find an answer.

On my WordPress site, the URL for tags is mysite.com/tag/tag-term. This displays fine using the tag.php template. However, If I just go to mysite.com/tag/ I get a 404 error. It is the same for custom taxonomies I have. For example, I have custom taxonomy of developer so if I goto mysite.com/developer/term it loads content under that term using taxonomy-developer.php template. But going to mysite.com/developer/ returns a 404.

Is there a template I can use, or some other method to get WordPress to display a list of terms if someone goes to the /tag/ or /taxonomy/ part of the URL?

Thanks