It is mostly a question of inertia; we've been busy making sure that our customers have what they need, and continue to be willing and able to fund our R&D efforts, since 1983. We agree it is time to open things up a little, although FOSS remains impractical at this point in time. The free non-commercial (but "registered") release of v15.0 is the first step. Later this summer I hope we will make the un-registered version available on more platforms and probably a bit less annoying too / Morten Kromberg (CXO, Dyalog Ltd)