The proof development environment Ω-MKRP is intended to lend automated assistance to mathematicians in one of their main activities - the proving of mathematical theorems - in such a way that the system is a help, not a hindrance. Among the requisites for such a system are : an expressive object language ; a way to speak abstractly about proof plans ; a human-oriented presentation of constructed proofs ; extensive assistance in filling proof gaps. The Ω-MKRP system presented in the following is an attempt to meet these requirements by fusing the paradigms of fully automated, interactive, and plan-based theorem proving into a single framework. This article gives a survey of our work with this system.