ID	Supporting Software	Size	Download
1	Sun Java2 Runtime Environment(J2RE) For Windows	13.1MB	Download
2	Sun Java2 Runtime Environment(J2RE) For Linux	17.6MB	Download
Sun Java2 Runtime Environment(J2RE) is necessary for viewing molecular structures, You can choose to install J2SDK(bigger) or J2RE(smaller). They are also available on www.sun.com