If you need a markbook for a Mac you can download a free trial copy of the Teacher's Personal Markbook for OS X right now. No registration required, no email address needed, just click on the link below to download the install file.
This is a time limited version and while it is fully featured, you are limited to using it for a 30 day trial. Of course, once you discover how convenient the TPMX is and how it saves your time, you can register your copy at the Purchase TPMX page for a one time low cost of $39 AUD. (Approximately 31 EUR or 41 USD.)
In step 3, if you need to install the application somewhere else, you can drag the folder to another location.
Now that you have installed the program you may want to start using it straightaway for marks and grades, or you may prefer to first follow the Tutorial in the Help for an introduction.
Download Teacher's Personal Markbook for OSX
(6.8 MBytes) It's Free!