function __init__()
    include(joinpath(@__DIR__, "backends", "plotly.jl"))
    include(joinpath(@__DIR__, "backends", "gr.jl"))
    include(joinpath(@__DIR__, "backends", "web.jl"))

    @require GLVisualize = "4086de5b-f4b6-55f3-abb0-b8c73827585f" include(joinpath(@__DIR__, "backends", "gr.jl"))
    @require HDF5 = "f67ccb44-e63f-5c2f-98bd-6dc0ccc4ba2f" include(joinpath(@__DIR__, "backends", "hdf5.jl"))
    @require InspectDR = "d0351b0e-4b05-5898-87b3-e2a8edfddd1d" include(joinpath(@__DIR__, "backends", "inspectdr.jl"))
    @require PGFPlots = "3b7a836e-365b-5785-a47d-02c71176b4aa" include(joinpath(@__DIR__, "backends", "pgfplots.jl"))
    @require PlotlyJS = "f0f68f2c-4968-5e81-91da-67840de0976a" include(joinpath(@__DIR__, "backends", "plotlyjs.jl"))
    @require PyPlot = "d330b81b-6aea-500a-939a-2ce795aea3ee" include(joinpath(@__DIR__, "backends", "pyplot.jl"))
    @require UnicodePlots = "b8865327-cd53-5732-bb35-84acbb429228" include(joinpath(@__DIR__, "backends", "unicodeplots.jl"))

    # ---------------------------------------------------------
    # IJulia
    # ---------------------------------------------------------

    @require IJulia = "7073ff75-c697-5162-941a-fcdaad2a7d2a" begin
        if IJulia.inited

            """
            Add extra jupyter mimetypes to display_dict based on the plot backed.

            The default is nothing, except for plotly based backends, where it
            adds data for `application/vnd.plotly.v1+json` that is used in
            frontends like jupyterlab and nteract.
            """
            _extra_mime_info!(plt::Plot, out::Dict) = out
            function _extra_mime_info!(plt::Plot{PlotlyJSBackend}, out::Dict)
                out["application/vnd.plotly.v1+json"] = JSON.lower(plt.o)
                out
            end

            function _extra_mime_info!(plt::Plot{PlotlyBackend}, out::Dict)
                out["application/vnd.plotly.v1+json"] = Dict(
                    :data => plotly_series(plt),
                    :layout => plotly_layout(plt)
                )
                out
            end

            function IJulia.display_dict(plt::Plot)
                output_type = Symbol(plt.attr[:html_output_format])
                if output_type == :auto
                    output_type = get(_best_html_output_type, backend_name(plt.backend), :svg)
                end
                out = Dict()
                if output_type == :txt
                    mime = "text/plain"
                    out[mime] = sprint(show, MIME(mime), plt)
                elseif output_type == :png
                    mime = "image/png"
                    out[mime] = base64encode(show, MIME(mime), plt)
                elseif output_type == :svg
                    mime = "image/svg+xml"
                    out[mime] = sprint(show, MIME(mime), plt)
                elseif output_type == :html
                    mime = "text/html"
                    out[mime] = sprint(show, MIME(mime), plt)
                else
                    error("Unsupported output type $output_type")
                end
                _extra_mime_info!(plt, out)
                out
            end

            ENV["MPLBACKEND"] = "Agg"
        end
    end
end