import bpy
import bgl
import blf

def draw():
    
    font_size = 16
    font_dpi = 72
    line_height = font_size * 1.25 # ensures a bit of space between each line
    
    # Draw 3 lines of text just below the selected object name in the 3D viewport.
    lines = ["The quick brown fox", "jumped over the lazy", "bug report"]

    
    # calculate the top and left position based on whether or not the toolbar and header is visible so the text aligns with the built-in viewport text
    tool_region = None
    header_region = None
    window_region = None
    
    for r in bpy.context.area.regions:
        if r.type == "TOOLS":
            tool_region = r
        if r.type == "HEADER":
            header_region = r
        if r.type == "WINDOW":
            window_region = r
            
    desired_top = int(window_region.height) - 100
    left = 30

    if tool_region != None:
        left = tool_region.width + left
    
    if header_region != None:
        desired_top -= header_region.height
            
    
    blf.size(0, font_size, font_dpi)
    actual_top = desired_top - int(line_height * len(lines))
        
    for i, line in enumerate(lines):
        y_offset = (i - len(lines)) * -1
        blf.position(0, left, actual_top + (y_offset * line_height), 0)
        blf.draw(0, line)


try:
    bpy.types.SpaceView3D.draw_handler_remove(draw, "WINDOW")
except:
    # wasn't added yet, first run.
    pass

bpy.types.SpaceView3D.draw_handler_add(draw, (), 'WINDOW', 'POST_PIXEL')