The Sawtooth PoET consensus engine implements a CFT (Crash Fault Tolerant) variant of PoET which does not use a TEE. A future version of the consensus engine which also implements full BFT (Byzantine Fault Tolerant) features using an SGX enclave is in development.
The current PoET specification is available in sawtooth documentation
Documentation for how to use Sawtooth PoET is available here: https://sawtooth.splinter.dev/
Sawtooth software is licensed under the Apache License Version 2.0 software license.