In the domain of Technology-Enhanced Learning (TEL) a current research focus is on widget-based personal learning environments (PLE). Learners mash-up their favorite Web widgets to complete learning applications running in any Web browsers. Furthermore, learners socialize, communicate or even collaborate with their peers using real-time technologies. In the context of the EU large-scale integrating Open Source project ROLE (Responsive Open Learning Environments; http://role-project.eu; http://sourceforge.net/projects/role-project/), we employ XMPP in combination with recent Web technologies (e.g. XMPP over WebSocket) on a wide basis to realize communication and collaboration use cases within such browser-based PLE. Beneath the usage of regular features such as roster lists, online presence, IM and MUC we developed a framework for Interwidget Communication (IWC) based HTML5 Web Messaging (local) and XMPP PubSub (remote) as well as a payload format inspired by Google Android Intents. Developers can thus design their widgets to communicate with each other even across multiple users and browsers. This framework can optionally be enhanced with trust-awareness features. In this talk we present the results of our work with a focus on remote interwidget communication and report on our experiences with XMPP over BOSH/WebSocket.