In this paper we present DOMMLite - an extensible domain specific language (DSL) for static structure definition of data base oriented applications. The model-driven engineering (MDE) approach, an emerging software development paradigm, has been used. The language structure is defined by the means of a meta model supplemented by validation rules based on Check language and extensions based on Extend language, which are parts of the openArchitectureWare framework [1]. The meta model has been defined along with the textual syntax, which enables creation, update and persistence of DOMMLite models using a common text editor. DSL execution semantics has been defined by the specification and implementation of the source code generator for a target platform with an already defined execution semantics. In order to enable model editing, a textual Eclipse editor has also been developed. DSL, defined in this way, has the capability of generating complete source code for GUI forms with CRUDS (Create-Read-Update-Delete-Search) and navigation operations [2,3,4,5].