2. Cloud*MOVED TO* https://github.com/sagemathinc/cocalc
3. SagecellThe Sage Cell Server---providing a way to embed Sage computations into any web page.
4. SagenbSage Notebook (flask), docs in $SAGE_LOCAL/share/doc/sagenb/index.html
5. SageMirror of the Sage source tree -- please do not submit PRs here -- everything must be submitted via https://trac.sagemath.org/
8. more-sagemath-tutorialsMore SageMath Tutorials: A place to share and evolve tutorials for Sage, with the aim to contribute them to Sage