From the homepage:
A scalable, fast, consistent graph store
Weaver is a distributed graph store that provides horizontal scalability, high-performance, and strong consistency.
Weaver enables users to execute transactional graph updates and queries through a simple python API.
Alpha release but I did find some interesting statements in the FAQ:
Weaver is designed to store dynamic graphs. You can perform transactions on rapidly evolving graph-structured data with high throughput.
Examples of dynamic graphs?
Think online social networks, WWW, knowledge graphs, Bitcoin transaction graphs, biological interaction networks, etc. If your application manipulates graph-structured data similar to these examples, you should try Weaver out!
High throughput?
Our preliminary experiments show that Weaver achieves over 12x higher throughput than Titan on an online social network workload similar to that of Tao. In addition, Weaver also achieves 4x lower latency than GraphLab on an offline, graph traversal workload.
Alpha release has binaries for Ubuntu 14.04, the is a discussion list and the source code is on GitHub. Weaver has a native C++ binding and a Python client.
Impressive enough statements to start following the discussion group and to compile for Ubuntu 12.04 (yeah, I need to upgrade in the new year).
PS: There are only two messages in the discussion group since this is its first release. Get in on the ground floor!