The Stream .NET SDK by Stream communicates with the API to access data related to activity streams and news feeds. It contains installation with NuGet and usage. Documentation available at http://getstream.io/docs/
Purlem, personalized landing page and marketing service, has launched The Purlem API that gives developers access to most of Purlem's personalization features. Purlem was born out of frustration with the cost and complexity involved in pURL development. Now available through an API, Purlem has taken more barriers out of pURL creation and maintenance.
Personalization tools have long existed allowing marketers to custom tailor online marketing to consumers. However, business to business marketing has eluded personalization tools until Demandbase created its Real-time Identification service: a "service [that] bridges the gap between known and anonymous web visitors by identifying and segmenting the companies visiting a website, and providing detailed, targetable business attributes in real-time." Now, Demandbase is making its Real-time Identification platform available to third party developers via an the Demandbase API.