Just a couple thoughts that came to me while checking out the new tagging system...
First, hooray for nested tags! But there are a couple things about their behavior that could be tweaked.
- The subtags for the "Dev" tag ("PHP" and "JS") appear above "Dev" in the tag selection dialog, so they look like they're sub tags for "UX" instead. Below would be more natural.
- It's possible to add a subtag without it's parent. For example, you can choose "Dev", then choose "PHP", then remove "Dev" ... you're left with "PHP". Is this intentional?
You may have noticed these already, but just in case...