A new open-source, embbeded datastore library with over 70 commands called "Vedis" is a very interesting new project that is very similar, in concept, to Redis. It's virtually a subset of Redis but without the networking layer.
Vedis features from the project page:
Serverless, datastore engine.
Transactional (ACID) datastore.
- Built with over 70 commands similar to the standard Redis commands.
Single database file, does not use temporary files.
Cross-platform file format.
Standard Key/Value store.
Support for on-disk as well in-memory datastore.
- Thread safe and full reentrant.
- Simple, Clean and easy to use API.
- Support Terabyte sized databases.
The library, written in C, doesn't have sorted lists yet. It should be great for usage in embedded devices without the infrastructure of a desktop computer.