
Every machine I have can be accessed with this, because TeamViewer is available for Windows, Mac OS, and Linux. This works well for intermittent access (such as accessing my Macbook Air located in the shop from either a PC or Mac inside the house, but is not ideal for full time use on two machines side-by-side. When you finish, shut down the connection. Install on each Mac, remember the "partner ID" for whichever you don't have a keyboard/mouse on, change the access password from the default if desired (this is a separate password from the Apple ID), and access the second from the first. One way (for non-commercial users, commercial costs $) is to use TeamViewer.

There are a number of ways to accomplish this.
