Clear Containers vs SmartOS: What are the differences?

Clear Containers: Use the isolation of virtual-machine technology along with the deployment benefits of containers. We set out to build Clear Containers by leveraging the isolation of virtual-machine technology along with the deployment benefits of containers. As part of this, we let go of the "generic PC hardware" notion traditionally associated with virtual machines; we're not going to pretend to be a standard PC that is compatible with just about any OS on the planet; SmartOS: Converged Container and Virtual Machine Hypervisor. It combines the capabilities you get from a lightweight container OS, optimized to deliver containers, with the robust security, networking and storage capabilities you’ve come to expect and depend on from a hardware hypervisor.

Clear Containers and SmartOS can be primarily classified as "Virtual Machine Platforms & Containers" tools.

Clear Containers is an open source tool with 421 GitHub stars and 58 GitHub forks. Here's a link to Clear Containers's open source repository on GitHub.