Disk images of ISO 9660 file systems (ISO images) are a common way to electronically transfer the contents of CD-ROMs/DVDs. They often have the filename extension .iso (though not necessarily), and are thus commonly referred to as ISOs.
You can boot your VMs directly from ISO image without using cds/dvds. you may find winiso, power iso and deamon tools very handy to work out with iso files.
WinSCP and Putty are cool tool that allows Windows machines SSH access to ESX systems. WinSCP tool is very intuitive and familiar looking if you use Norton Commander or Windows Explorer. We use this tool for transferring ISO images and other files such as .flp (floppy images) onto our ESX Server. Putty is used to telnet host without going to data centre to log on to host from console.
NewSID is a free tool. You need to run this tool if you clone template virtual machines. When you run it you can select a random SID. you will be given the option to reboot the computer after the new SID is applied. The SID will then be applied to the virtual machine. After the VM reboots, you shouldn’t run into any issues regarding SID or name problems.
Veeam ESX backup is a nice tool to backup ESX host. You will get free version and purchased version of Veeam backup.
There are lots ESX third party tools available to make your task easy and comfortable. Among them, I used SolarWinds ESX monitoring tools, Vizioncore vRanger and VMTS tools.
You may google and find heaps freeware that works same as purchased version of application.