NooJ is a linguistic development environment that allows linguists to formalize several levels of linguistic phenomena: typography and spelling; lexicons of simple words, multiword units and discontinuous expressions; inflectional, derivational and productive morphology; local and structural syntax, transformational and semantic analysis and generation. For each of these levels NooJ provides linguists with one formal framework specifically designed to facilitate the description of each phenomenon, as well as parsing/development/debugging tools designed to be as computationally efficient as possible, from Finite-State machines to Turing machines. This approach distinguishes NooJ from other computational linguistic frameworks which provide a unique formalism based on a compromise between power and efficiency. As a corpus processing tool, NooJ allows all researchers and professional to extract information from general or technical corpora by applying sophisticated queries based on concepts rather than word forms and build indices, add semantic annotations, perform statistical analyses, etc. MONO version of NooJ is operative on all platforms that support MONO.