You might want to try Aptana Studio, I used little and mostly for straight HTML and Python, but it is also an editor for (or assists with) SVG, CSS, PHP, JSON, JavaScript
[Update] Forgot the link:
http://www.aptana.com/products/studio3[/Update]
"The five senses obstruct or deform the apprehension of reality."
Jorge L. Borges?
"Premature optimization is the root of all evil in programming."
Donald Knuth, repeating C. A. R. Hoare
"To die for a religion is easier than to live it absolutely"
Jorge L. Borges