If your work involves working on multiple computers at the same time, then you would find ShareMouse immensely useful. It is a free software that can share your mouse or keyboard over multiple computers. This way you can control applications running on different computers with just a single mouse or keyboard. Through this software, all the keyboard inputs and mouse movements on your main computer are transmitted to other selected computers.
You can download ShareMouse from the keyboard and mouse sharing website. The download is available both as a setup installer and a portable application of very small size. It is available both for Windows and Mac. In Windows, you can extract the contents of the downloaded ZIP file and run sharemouse.exe from there. It immediately starts listening to UDP port 1046 over which all the network traffic is sent. You have to run the same application on all the computers that you want to control. It should also be mentioned that all the computers should be connected over a local network (for example over the Ethernet) for the ShareMouse to work.
In the ShareMouse settings, you can choose a hotkey to switch the monitors, data synchronization (drag-n-drop of files and clipboard sharing), choose a different UDP port, choose online update settings etc. There is also a security setting that lets you control the other monitors only after entering a password.
In the settings window, you can click on the Monitor Manager button to open its window. The Monitor Manager allows you to organize your monitor layout.
The ShareMouse, despite its name having only mouse, allows you to share your keyboard too. You can control up to a maximum of 26 computers together. The network traffic of ShareMouse is encrypted so it provides the basic protection against man-in-the-middle attacks. You can control a mix of computer types with it. For example, in a network of Mac and Windows PC, you can share your mouse and keyboard between Mac and Windows PC’s.
You can download Share Mouse from http://www.keyboard-and-mouse-sharing.com/.