It's at an early stage, but I will appreciate some feedback.
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syntax highlighting, (yes, highlight.js based)
normal text (I don't understand what this means, epiphany is markdown based)
showing graphs (yes, you can write js or python, matplotlib is supported)
matrices (half , there is no official api, but since you can write programs on it, this should be doable),
images .
support LaTeX too, (it supports equations in latex.)