Very nice List about a lot of Free Tools

Virtualization Monitoring
Monitor any virtual machine or hypervisor from VMWare and Xen. Monitoring critical resources of hosts or guests.

Use this backupscript in the console

The best and fastest tool to copy files from and to the ESX Host.

To view all folders: check 'View -> All folders' menu item to see all the directories.

This script offers a lot of options and was already on ESX 2.x often used!

Free utility to revert multiple snaphosts

This is a file conversion tool it will not make any modifications to the source image such as uninstalling VMTools etc... but it will leave your source VMDK un-touched so you can continue to use it.

Free SSH file transfer, terminal and tunneling

WinSCP is an open source free SFTP client for Windows using SSH.
Norton like Userinterface. Somtimes some problems when transfering files.

To work on the console the right free tool.