DeepaMehta 4.2 is a maintenance release that brings bug fixes and additions to the Plugin Development Framework. New is a facility for Custom Events: plugins can define its own specific event types. Furthermore this release is compatible with 2 new plugins (optional install): WebSockets provide plugin developers the basis for server push, and the experimental D3.js Renderer plugin demonstrates how the D3.js library can be utilized for rendering topicmaps. It features a SVG-based animated force layout for automatic topic positioning. For detailed information about this release (and about the 4.2 version number) see the release notes.