Netscape released version 4.5 of it's popular web browser this week. Users will find that it is much faster and has more features than previous versions, but also requires more ram. Netscape also announced that 4.5 and all future versions will be for PowerMac only. Older Macs will still be supported by Communicator 4. A Beta program is an early release that is intended for people who are very experienced with the product or are skilled at computers.
Companies release beta programs so users can help debug it before the final release.
Alpha and Developer programs are much like Betas, but buggier. Do not download a beta unless you are very comfortable with your computer and adept at fixing it if something happens. If so, check out Trendsetter Software's homepage. Trendsettee is a maker of professional stock analysis software for the Mac. If you are an amateur investor, try Stock Tracker.