All of the HSC courses now come in a single version for Windows, Mac, and Linux. The files are distributed on an 8GB reusable flash drive, so they are accessible on computers that do not have CD/DVD drives.
Earlier versions of the HSC project had videos in avi format, which did not play well in Quicktime. However, all of the videos in all of the courses have now been converted to mp4 format, so they should play in any media player, including Quicktime. Some media players allow more fluent scanning and frame selection than others, which can be significant if you are searching or replaying sections of a video. If your media player does not perform well in this way, try downloading the VLC Media Player, which is available for Windows/Mac/Linux.
The spreadsheets used in the HSC courses were constructed with Libre Office (a branch of the Open Office project), a FREE, open source alternative to Microsoft Office, however, the files are saved in .xls format to be compatible with the Microsoft Office spreadsheet, Excel. There are Windows, Mac, and Linux versions of Libre Office. Most Linux distributions come with Libre Office installed.
Equation Graphing Software
A graphing program used in some of the HSC videos is Graphmatica, which is a Windows program. However there is a very powerful 2-D and 3-D graphing program that comes bundled with the OS X operating system on the Mac, called Grapher. Grapher can be used on your computer wherever the videos use Graphmatica. Another option is to use Geogebra. Anything that can be displayed in Graphmatica can be displayed in Geogebra.
The HSC Geometry course uses pdf files for its Solution Guide. PDF support comes bundled with the operating system on the Mac, so this should not be an issue.
The HSC Geometry and Precalculus courses make heavy use of Geogebra, which is FREE for student use. Geogebra is available for Windows/Mac/Linux at Geogebra.org.