The short answer is that Temporal is a fork of Cadence by the original founders of the project. The Temporal fork also has a VC backed company behind it. The Temporal is still an open-source project under MIT License. We believe the success of the open source project is essential for the success of the company, so we are putting significant resources into its development.

We spent almost year working on various improvements before declaring the first production release. The most important technical difference is that Temporal uses gRPC/Protobuf when Cadence is TChannel/Thrift. One implication is that TChannel did not support any security and Temporal supports mTLS. We are currently working on a comprehensive security story.

Here is a stackoverflow post that has more details about this: https://stackoverflow.com/questions/61157400/temporal-workfl....