Download Flash. The Flash player allows you to experience interactive multimedia through your Web browser, such as Evolution activities like Darwin's Diary and Origins of Humankind.

Download Shockwave. The Shockwave player allows you to experience interactive multimedia, including audio, video, animations, and puzzles, through your Web browser in activities like Sex and the Single Guppy.

Download QuickTime. The QuickTime file format allows you to listen to sound files or see video files over the Net without having to wait for the whole file to download.

Download RealPlayer. The RealMedia streaming file format allows you to listen to sound files or see video files over the net without having to wait for the whole file to download.

Download Acrobat Reader. Using the free Acrobat Reader software, available for Macintosh, Windows, and UNIX platforms, you can read and print the pages on your printer in a manner that accurately reproduces the printed Teacher's Guide, including fonts, pictures, and illustrations, and reproduces them much more accurately than standard HTML Web pages can.