I personally use emacs , git , github and
gitbook.io.��
There is a pillar preview for GT tools (as Sven mentioned), but I have not tested thoroughly . So maybe editing pillar inside Pharo is not that far away. Overall pillar syntax is very simple and quite small so it should not be that hard to implement for Pharo. Afterall Pillar is implemented in Pharo. But still Pharo cannot compete with emacs for editing text . Which is fine because nothing stops me from using both Pharo and Emacs and I love both tools very much.��
My dream would be not to use Pillar at all and Pharo instead have a documentation tool like LibreOffice that allow you to export to Pillar files. Why meta-tag or code when you can design ? ;)��