\definefontfamily [mainface] [sans] [Ubuntu] [regularfont=ubuntu,italicfont=ubuntuitalic,boldfont=ubuntubold]
\definefallbackfamily [mainface] [math] [Ubuntu] [preset=math:lowercaseitalic,tf=name:ubuntu]
\definefontfamily [mainface] [math] [Latin Modern Math]
\setupbodyfont[mainface]
\starttext
$ abc \max$ abc max
\stoptext
I am also interesting by knowing where I can find all the features "preset=math:" possible.
Flavien.