] Eclipse is a free download, and is available on a number
] of platforms. Since IBM launched Eclipse in November
] 2001, more than 18 million download requests have been
] logged from over 125 countries.
]
]
] A growing consortium of high-profile companies and
] organizations are actively supporting and extending
] Eclipse's ongoing development and giving the platform
] momentum. These organizations contribute support and
] technology, and they determine the direction and scope of
] Eclipse's growth.

Apple's Eclipse page. Eclipse is an IDE, and it is built with JFace/SWT. The GIMP is to Gtk+ as Eclipse is to Jface/SWT. They provide a not-so-slow replacement for SWING. Java doesn't have to be slow.

Eclipse and Mac OS X: A Natural Combination