This thesis reports on the design, implementation and evaluation of a new interactive Z environment that is integrated into the Eclipse environment. The Z language is a formal specification notation that is used to describe and model computer-based systems. For the widespread use of Z, it is desirable to integrate Z support with a mature and popular editing environment, such as Eclipse. Eclipse was chosen as the basis for the new Z environment because it is widely used, it provides rich functionality and it is designed to be extensible. The Z environment described in this thesis extends Eclipse to provide a large set of useful features for editing and analyzing Z specifications, such as a table of Z symbols, constant detection of syntax and type errors, outlining facilities, cross-referencing of Z names and conversion between different Z markups. User feedback shows that the resulting Z environment is helpful for editing and correcting Z specifications. The development of the Z support for Eclipse is a part of the CZT (Community Z Tools) project, which is a Java framework for building Z tools and provides parsers, typecheckers and other Z tools.