This chart only counted (egrep -v '^$' file | wc -l) the uncompressed JavaScript files, jquery-*.js, (jquery.)effects.*.js and (jquery.)ui.*.js. (localization, demo, test, etc. files are not included) The release dates may not be accurate because some are hard to find out. You can see there are three data lines for jQuery UI from chart, they need specific jQuery versions to work, which are noted within parentheses, e.g. UI (1.3) means those jQuery UI releases require jQuery 1.3.x.