stylesheet.xml

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over" background-color="steelblue">

    <Style name="style">
        <Rule>
            <PolygonSymbolizer fill="white" />
            <LineSymbolizer stroke="grey" stroke-width=".2" />
        </Rule>
    </Style>

    <Layer name="world" srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over">
        <StyleName>style</StyleName>
        <Datasource>
            <Parameter name="file">data/world_merc.shp</Parameter>
            <Parameter name="encoding">iso-8859-1</Parameter>
            <Parameter name="type">shape</Parameter>
        </Datasource>
    </Layer>

</Map>