Twitter has launched its year-end roundup, holding a mirror up to the microblogging world and highlighting the hot topics of 2013. The most retweeted tweet of the year came when Glee's Lea Michele broke her silence on the death of her co-star and partner Cory Monteith, who died of a heroin and alcohol overdose in July; the tweet peaked at 408,266 retweets, though it's since fallen to around 394,000.

The second most retweeted tweet also related to a high-profile passing — this time that of Fast and Furious actor Paul Walker, whose death in a car crash was announced by his publicists on Twitter in a message retweeted 400,367 times so far. Despite Twitter's continuing growth, however, President Obama's reelection victory tweet remains the most retweeted of all time.

#Music is the number one trend

The apparent failure of Twitter's much-hyped #Music app hasn't stopped #music from being the number one "top trend" of 2013; #nowplaying continues the musical theme at number three. Number two goes to #tcot, a hashtag that stands for "Top Conservatives on Twitter" and helps right-wing people find like-minded users on the service; the tweet embedded below is a currently trending example.

Rounding off the top five trends are two that limit themselves to a single day of the week: TGIF, or "Thank God it's Friday," and #tbt, or "Throwback Thursday," which has become a Twitter tradition in which users post old pictures of themselves.

Twitter has also highlighted some of the more notable names that made their way to the service in 2013. Among those making their first tweets were Stephen King, Bill and Hillary Clinton, Robin Williams, Kobe Bryant, both of the year's Popes, Roger Federer, Madeleine Albright, and Sarah Jessica Parker. Earlier today Bill Clinton greeted another famous arrival to Twitter — the man he took over from as President, George H.W. Bush.