The nature of Web data is changing. The popularity of News feeds, and Social Media, the rise of the web of things and the adoption of sensor technologies are examples of streaming data that reached the Web Scale. The different nature of streaming data calls for specific solutions to problems like data integration and analytics. We need streaming-specific web resources: new vocabularies to describe, find and select streaming data sources and; systems that can cooperate in real-time to solve streaming processing tasks. To foster interoperability between these streaming services on the web, we propose the Vocabulary & Catalog of Linked Streams (VoCaLS). VoCaLS is a three-module ontology to (i) publish streaming data following Linked Data principles, (ii) to describe streaming services and (iii) track the provenance of the stream processing.