From the apache site, "Apache Accumulo is based on Google's BigTable design and is built on top of Apache Hadoop, Zookeeper, and Thrift." So, it's not like they

From the apache site, "Apache Accumulo is based on Google's BigTable design and is built on top of Apache Hadoop, Zookeeper, and Thrift." So, it's not like they started from zero, looks more like the early alternatives weren't a good fit. Furthermore i doubt any of the alternatives were very impressive in 2008.