You can use it for life. License can be transferred.
With the license you can download all the following versions:
vBulletin 5.5.x Connect
vBulletin 4.x Forum, CMS and Blog
vBulletin 4.x Forum Only
Simplified site setup and customization
The new Site Builder makes it easier than ever to create and manage a site. Customizable page templates, drag-and-drop configuration and inline site editing simplify page layout.
Stylish new interface includes stream of activity and increased social interaction
Enhanced social functionality includes groups, new user profiles, comment functions, an integrated messaging center, real-time updates, and more.
Extended photo and video capabilities
The new interface invites users to upload photos and videos quickly, which expands the content on vBulletin sites.
The integrated mobile optimized version allows smartphone visitors to stay longer.
Improved architecture provides better performance and easier customization
Built-in SEO helps maximize search traffic