I love the idea of a visual IDE for web apps, but Tersus seems so heavy, with so many dependencies. This may be a stupid question, but is there a good OS X-bas

I love the idea of a visual IDE for web apps, but Tersus seems so heavy, with so many dependencies. This may be a stupid question, but is there a good OS X-based visual IDE out there for creating web apps? I don't care if it's for PHP or Python or anything else - I want to learn to create web apps, and I have to start somewhere. I'm trying out both Django and RoR, but it would be awesome if there were a visual way to start putting the pieces of an app together, and then building up the code from within.