This looks great! Good timing too, since Roam has recently closed its doors to new signups. I've been looking for a new notetaking / PKM / Markdown app recently, but unfortunately all apps out there fall short in at least one of the following criteria:
* bidirectional [[wiki links]]
* support for both inline and display math
* customizable themes / CSS
* rich formatting beyond markdown (e.g. wrap content in
* WYSIWYG (crucial for documents with tons of math and rich formatting as above) including wysiwyg editing of tables
Tools I've tried that come close but aren't quite good enough:
* Jupyter Lab / Notebooks
* Typora
* Roam
* OneNote (just let me write $\LaTeX$ math!)
It's actually been quite frustrating. because some apps are soooo close to what I need, but they're closed-source so I'm powerless to make the small improvements I need. My current workflow for notetaking uses a pretty suboptimal combination of Overleaf, Typora, and OneNote. I'd really like to be able to replace all three with a single tool. At the moment, the only thing that comes close is a Chrome tab with document.designMode="on".
To the Obsidian team: Please add inline math support and consider WYSWIG!
It appears to match all of your requirements, and is scriptable. It's also strongly FOSS, in the AGPL sense. It also has the ability to self-host a sync server.