Abstract. This paper introduces PG/Eclipse; a sophisticated new interface for interactive theorem provers, offering users a rich set of proof development tools. It is based upon two complementary frameworks. The first is PG/Kit, a generic communication framework for connecting theorem provers and interfaces. PG/Kit should allow straightforward adaptation to most interactive theorem provers. Moreover, by separating interface development from proof engine development, this framework should facilitate the development of both. The second is Eclipse, a sophisticated open source framework for building IDEs. Eclipse is highly modular and extensible, making it a good platform for interface research. Using it has allowed us to provide a rich range of interface features. These frameworks correspond to the twin goals of this project: to define a clear separation between provers and interfaces, and to translate programming development tools to a theorem proving environment
