Application generator is useful for generating many similar applications, but building an application generator requires large programming effort. To solve the problem, we developed LACIE, a framelet (lightweight framework) that enable developer to quickly write an application generator. LACIE offers components for text transformations common in application generators. The components are document input processor, language or templates processor, and code generator. To further reduce input errors, LACIE also provides error checker that matched input agains terror pattern. With our approach, we are able to reduce coding time (for building a generator as well as the target applications) and we are able to obtain error free source code. Our approach is applicable for other cases where software package consists of large amount of small programs.