We report progress on the development of Actress, a compiler generator based on action semantics. It consists of a number of modules, written in SML, that can be composed to construct either an action notation compiler or a simple compiler generator. We also outline current and future developments that will improve the quality of the generated compilers. 1 Introduction We define a compiler generator to be a tool that constructs a compiler automatically, given a syntactic and semantic description of the source language. This definition emphasizes the fact that the compiler is not written by a programmer, but generated from a formal description of the language. Ideally, this formal description is one that was written by the language designer and is consulted by users of the language. We can generate an efficient syntactic analyser automatically from a syntactic description, using tools such as lex and yacc. However, generating a code generator from a semantic description is much more d...