Modern IDEs increase developer productivity by incorporating many different kinds of editor services. These can be purely syntactic, such as syntax highlighting, code folding, and an outline for navigation; or they can be based on the language semantics, such as in-line type error reporting and resolving identifier declarations. Building all these services from scratch requires both the extensive knowledge of the sometimes complicated and highly interdependent APIs and extension mechanisms of an IDE framework, and an in-depth understanding of the structure and semantics of the targeted language. This paper describes Spoofax/IMP, a meta-tooling suite that provides high-level domain-specific languages for describing editor services, relieving editor developers from much of the framework-specific programming. Editor services are defined as composable modules of rules coupled to a modular SDF grammar. The composability provided by the SGLR parser and the declaratively defined services allows embedded languages and language extensions to be easily formulated as additional rules extending an existing language definition. The service definitions are used to generate Eclipse editor plugins. We discuss two examples: an editor plugin for WebDSL, a domain-specific language for web applications, and the embedding of WebDSL in Stratego, used for expressing the (static) semantic rules of WebDSL.