Many of us are users of large-scale machine translation (MT) systems, but some may want to create a customisable MT system based on our own bilingual resources. I created a mini MT engine that enables you to import a simple text file with bilingual expressions (including sentences, clauses, phrases and words), and the engine will translate your source text with the expressions in the file. Written in JS, the engine supports offline translation and adopts a simplified version of the "substitution" MT approach presented in one of my papers (see this). Let's give it a try here.