OpenStack is an open and scalable cloud operating system for building public and private clouds. It provides both large and small organizations an alternative to closed cloud environments, reducing the risk of lock-in associated with proprietary platforms.
Apart from the main features, I really appreciate OpenStack's microservices architecture and its flexibility for deployment with different tools.
I like its integration with GitLab and its simplicity. OpenStack has a lot of third-party libraries that it uses.
There are many services that can be directly used which are not available in VMware.
The initial setup isn't too difficult.
The most valuable feature is the customization. With the customization you can really give the customers what they want.