We have posted here the most recent Rainbow newsletter in Adobe Acrobat Reader (.pdf) format. Most computers now come with this software bundled. When you click on the link, Acrobat Reader will either (depending on how you have your browser configured) launch automatically and present the newsletter on the screen for reading; or your browser will begin downloading the .pdf file onto your computer, which can then be launched separately and read through Acrobat Reader.
If you do not have Acrobat Reader, click here for a link to Adobe's download site--it's freeware and available in Mac (as well as Windows) versions.