Stellar is a platform that helps developers in building financial products and applications. It features a decentralized distributed database, Multisig, and smart contracts. Horizon is Stellar's client-facing API server that connects to the ledger (Stellar Core). The Stellar Horizon API is REST based and returns data in JSON format. It is used to submit transactions to Stellar Core, check the status of accounts, subscribe to event streams, among other functions.
Six APIs have been added to the ProgrammableWeb directory in several categories including Home Automation, Financial, Transportation, and Marketing. Also new to the directory are SDKs for OneSignal and Grepwords keyword service. Here's a quick summary of the recent additions.