API Libraries allow you to work with either the WebSocket Steemd API, or the cli_wallet API. They are available for many languages.
Be aware you don't need to run your own Steem daemon for most cases, you can just connect to a public one, such as Steem.WS ran by @Xeroc and @Jesta
- Piston - A powerful python API capable of making bots in just a few lines of code, and any other interaction with the Blockchain that you would require
- SteemJS (pharesim) - Unrelated to SVK's SteemJS. This offers nothing more than a very light JS API for connecting to the Steem WebSocket API.