Microsoft’s Macintosh Business Unit has published MSN Messenger 4.0 for Mac, the latest version of its free instant messaging software. It allows you to chat online with friends, family and co-workers who also have MSN Messenger accounts and can notify you when you receive new messages at your Hotmail e-mail account. It also offers the latest news and headlines from MSN. MSN Messenger 4.0 for Mac requires Mac OS X v10.2.8 or higher, 128MB RAM and 12MB hard drive space. You can download it from Microsoft’s Mactopia Web site.