The MIT license text is extremely short: you can do almost anything with the code (including closed-source commercial use); the only obligation is keeping the original copyright and license notice. The software is provided as-is, with no warranty from the authors.
Enclave is released entirely under MIT — which means more than free: anyone can audit every line of code, fork their own version, and verify that the data handling matches what's advertised.
Try it yourself in Enclave
Open it in your browser — no credit card, no install.