ClustrixDB vs Riak: What are the differences?
Developers describe ClustrixDB as "Clustered SQL database built for e-commerce". ClustrixDB is a scale-out SQL database built from the ground up with a distributed shared nothing architecture, automatic data redistribution (so you never need to shard), with built in fault tolerance, all accessible by a simple SQL interface and support for business critical MySQL features – replication, triggers, stored routines, etc. On the other hand, Riak is detailed as "A distributed, decentralized data storage system". Riak is a distributed database designed to deliver maximum data availability by distributing data across multiple servers. As long as your client can reach one Riak server, it should be able to write data. In most failure scenarios, the data you want to read should be available, although it may not be the most up-to-date version of that data.
ClustrixDB and Riak can be categorized as "Databases" tools.
Riak is an open source tool with 3.24K GitHub stars and 530 GitHub forks. Here's a link to Riak's open source repository on GitHub.