Nice that more of these are popping up; cf.<p><a href="https://news.ycombinator.com/item?id=37954707">https://news.ycombinator.com/item?id=37954707</a><p>But I would hope that these wouldn't all be online apps. Unfortunately, the open source community never managed to build a decent diagram application (although you can of course play with TikZ etc.).
I love this site for quick prototyping. Anyone knows of something similar (with quick rendering like this) that can be self hosted? I usually can't send any "architectural" information outside the company and fall back to less dynamic generation.