Hypertable is a high performance, open source, massively scalable database modeled after Bigtable, Google's proprietary, massively scalable database.
Column Family / Wide-Column
http://hypertable.org/
https://github.com/hypertable/hypertable
http://www.hypertable.com/documentation/
Zvents
US
2008
2016
Baidu
Commercial, Open Source
C++
C++, Java, Perl, PHP, Python, Ruby
Cloud BigTable
H-Store
GPL v3
https://en.wikipedia.org/wiki/Hypertable