Because the input accepted by BokehJS is an object graph, represented by declarative bits of JSON, any language that can generate the right JSON can generate Bokeh plots in the browser.
These are the currently known projects that expose Bokeh to languages other than Python. If you know of any that are not on this list, or if you want to work on a new language binding for Bokeh and need some help, please let us know.
The bokeh.jl binding is currently unmaintained. If you are interested in picking up the bokeh.jl work, please contact the core devs.