I think DRAKON solves the layout problem quite well (the specification also tries to cut down on excessive use of arrows).<p>[1] <a href="http:&#x2F;&#x2F;drakon-editor.sourceforge.net&#x2F;language.html" rel="nofollow">http:&#x2F;&#x2F;drakon-editor.sourceforge.net&#x2F;language.html</a><p>[2] <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10100932" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10100932</a>