The context-sensitive Help works without any additional modifications to the original WinHelp or HTML Help project. According to the RoboHelp help file, the API shares the same parameters with HTML Help and WinHelp, so "transitioning to another output only takes a few minutes of developer time."
Regardless of how much effort is required for the transition, the ability to launch topics into custom web browser windows is significant, and is a major step forward in providing context sensitive web-based help.