The most active WebObjects mailing lists are Apple's webobects-dev (for general WebObjects discussion), Wonder's wonder-disc (for Wonder usage discussion) and WOLips woproject-dev (for discussion about WOLips Eclipse plugins, woproject ant build tools and Entity Modeler).

Essential

• Apple hosted discussion about WebObjects development
• WOLips Mailing Lists (WOLips Users - Subscribe to woproject-dev)
• Project Wonder Discussion mailing list

Necessary

• Omni Group WO-dev mailing list
• Apple hosted discussion about deploying WebObjects applications

Beneficial

• Apple hosted announcements relating to WebObjects
• Project Wonder Subversion Commit Messages
• Google group for WebObjects Tips