loc.txt
# date iphone common ipad xxx
2010-02-08 9370 0 0 0 # iphone 1.0
2010-04-22 9602 0 0 0 # iphone 2.0
2010-06-03 9602 1354 4820 0 # ipad 1.0
2010-10-07 9602 1869 5536 0 # ipad 2.0
2011-03-01 8892 4041 9356 6046 # xxx 1.0
2011-05-06 8648 5973 6960 6046 # iphone 3.0
loc.gp
set terminal png size 600, 350
set output "loc.png"
set title "Projects Lines of Code"
set key left
set timefmt "%Y-%m-%d"
set format x "%Y-%m-%d"
set grid
set xdata time
set xtics rotate by -45
set xrange ["2010-03-01":"2011-06-01"]
plot "loc.txt" using 1:($5+$4+$3+$2) title "xxx" with filledcurves y1=0 lt rgb "#cc3333", \
"loc.txt" using 1:($4+$3+$2) title "iPad" with filledcurves y1=0 lt rgb "#cc9933", \
"loc.txt" using 1:($3+$2) title "Common Lib" with filledcurves y1=0 lt rgb "#669933", \
"loc.txt" using 1:2 title "iPhone" with filledcurves y1=0 lt rgb "#336699"
Drawing the chart
$ gnuplot loc.gp && open loc.png