The Slack Ruby SDK by Daniel Doubrovkine allows developers to integrate the Slack API and the Slack Real Time Messaging API into their Ruby applications. Usage examples are included in the documentation.
Technology blogger Mohamed Marwen Meddah wrote an interesting post recently on his StartUpArabia site: "The Importance of Having An API for Arab Startups". Mohamed notes that, thus far, relatively few Arab online startups have opened up their platforms through APIs. However, he believes that providing an API is crucial for Arab online services.