Remote desktop sharing for Mac and Windows 7

You can use  Microsoft Remote Desktop Connection Client to start remote desktop connection to Windows 7 in Mac.
Microsoft Remote Desktop Connection Client  can be downloaded from HERE:
 http://www.microsoft.com/en-us/download/details.aspx?id=18140
You can also get it from Microsoft Office 2011 for Mac,

For remote desktop connections  between Mac, you can use screen sharing features in Mac
Difference between screen sharing and remote desktop, you can see the the mouse moving from remote site in screen sharing..

For remote desktop connections  between Windows,  the application is built in Windows.