[0xndc]

I'm not sure how much of a priority you think this is, but the one main problem I have with SageMathCloud is the lack of good documentation. Mathematica, as a counterexample, has comprehensive, searchable and easily accessible (just hit F1) docs. I humbly submit that including a way to browse and search documentation - not just Sage-specific, but also for every library it includes - would go a long way towards making SMC more usable.