The described methods and systems allow to develop RTN-compatible grammatical models, for syntax or other linguistical levels, within one integrated development software environment (IDE) that is efficient, controllable and overviewable, because editing is done through a 2D/3D graphical user interface (GUI) with a pointing device (e.g. a mouse). Instantaneous evaluation of any fresh change to the grammar is carried out by re-parsing a test corpus of typically thousands of sentences, functioning as language examples to try to comply with, yielding immediate statistical feedback on parsability, thanks to an integrated new fast parsing method. Problematic corpus sentences can automatically be brought under the user's attention, who can visually zoom in on a problem spot in the model or the sentence without losing the overview. All this increases efficiency and quality in grammar model development. The integrated parser can also be used separately, for instance for machine translation, and is based on efficient concatenation of pre-calculated partial pathways through the RTN grammar. These are exhaustively calculated within reasonable preset limits.