"Lifetime License" means that you can use the purchased product as long as you want and as long as the computer you use it on meets the system requirements.
All Vovsoft products are sold with a lifetime (perpetual) license and updates (future versions) are always free of charge. A paid lifetime license will never expire. No strings attached.
Vovsoft products can be activated using both online and offline activation. The simplest one is online activation. You just enter your license key and it activates immediately if everything is alright. Vovsoft programs, once activated, do not need to connect to the online activation server again.
In cases where your computer is not connected to the internet or our activation servers are not working properly, you can activate offline. For offline activation, you need an offline activation code. To create your offline activation code, you can use the self-service Vovsoft Client Area.
If you are planning to enjoy our software for decades (even after the internet is gone and zombies are swarming around), we recommend that you create a virtual machine (using VMware, VirtualBox, Parallels), create an offline activation code for that computer and keep them safe.