- ChartIO
- 'WagonHQ, Modern SQL Editor' [1] (now aquired by Box)
- MetaBase [2,3]
- Redash [4]
MetaBase is the only one that I know of that is
- fully open source,
- mature (graphing options, permission model),
- still actively maintained, and
- both friendly to non-technical users and expert sql'ers alike
[1] https://news.ycombinator.com/item?id=9792464
[2] http://www.metabase.com [3] https://news.ycombinator.com/item?id=10425959