Ammyy Admin

Zero-Config Remote Desktop Software

Screenshots

Hunter's comment

If you have question that why ammyy admin then listen it has No installation required technique, it Works behind NAT and transparent for firewalls, Highest level of data transfer security, Built-in voice chat and file manager, and Control of unattended computers. For more information you need to check out website. This is best alternative of team viewer.

Link

http://www.ammyy.com/en/