Given a list of repositories, an install of git-bash (or equivalent) and gource + ffmpeg, combine all the repositories into one gource visualization with a logo.

hackathon.sh

#!/bin/sh
powershell -Command '
	Get-ChildItem -Directory | ForEach-Object {
		cd $_;
		git pull;
		cd ..;
		gource --output-custom-log "$($_.Name).txt" $_
	}
'
cat *.txt | sort -n > gource.log
gource -1920x1080 -o gource.ppm --hide-root --hide filenames,dirnames \
--stop-at-end --seconds-per-day 60 --logo logo.png --user-scale 5 gource.log
ffmpeg -y -r 60 -f image2pipe -vcodec ppm -i gource.ppm -vcodec libx264 -preset \
ultrafast -pix_fmt yuv420p -crf 1 -threads 0 -bf 0 hackathon.mp4
rm *.txt
rm gource*