SDS is my own version of a 'Steem Data Service', which can be used to easily request indexed blockchain data and to provide a more specific set of API's for SteemWorld and other apps.

It's being developed in NodeJS and allows developers to build/include custom 'Parser Modules', which (if activated in config) will automatically be called for each block, its transactions and contained operations (also virtual operations) of the blockchain.

So it can be used to build custom databases for different datasets/groups (for example for requesting all time rewards, voting behaviour details, searching/sorting posts by different keys and so on).

It's still in development and I'm not sure, when I will find enough time for finishing the first version, but I need it to be able to implement many planned features on SteemWorld.

For now I'm working mainly on SW to support the coming changes in HF21 and the exact curation rewards calculation. Way to many things to do currently...