Merkel's party (the "black" CDU, Christian Democrats--and it's Bavarian sister party the CSU) has been in a "grand alliance" with the SDP (Social Democrats) for a few years after neither party won enough seats by themselves or with an ally to govern alone. The CDU lost a bit this time, the SDP lost big.
The "yellow" FDP won big with nearly 15% of the vote (all of this is unofficial based on exit polls).
The "red" Left (former Communists) and the (okay, "green") Greens both did okay getting nearly a quarter of the vote between them.
The CDU/CSU will now form a black/yellow coalition with the FDP (personally, I favored the "Jamaican" coalition with the Greens too, but they said no). The Social Democrats wanted to form a "traffic signal" coalition (red/yellow/green), but the Free Democrats said no thanks this time round. The FDP used to be the kingmakers over the years: for many years in coalition government with the CDU/CSU then in the 80s in a coalition government with the SDP. I alluded to this dynamic in my HuffPo review of
For Liberty:
http://www.huffingtonpost.com/j-bradley-jansen/ifor-libertyi-examines-th_b_300868.html
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