Honduras held a general election (president and unicameral congress) today. Xiomara Castro has claimed victory in the presidential contest, although exit polls offer conflicting reports of which candidate is in the lead. Castro is the wife of Manuel Zelaya, the president who was overthrown in a coup in 2009.
Honduras has been dominated by two traditional parties (Liberal and National) throughout its history–when it has not been dominated by its military, that is. The country has been democratic since 1981, other than the 2009 coup. (The 2009 election was held on schedule afterwards.)
Whoever wins this election, one result will apparently be the shattering of this long partisan duopoly. Castro is running as the head of a new party/movement, called Libre, formed out of the 2009 crisis, while both traditional parties are also contesting with their own presidential candidates.
Honduras stands out as one of the few countries using proportional representation for its legislature to have a series of elections in which one party almost always wins a majority of the seats, and often also of the votes. The winning party has averaged 51.2% of the votes and 52.7% of the seats since 1981. Only in 2005 has the election not resulted in a majority in congress (48.4%) and only in 1997-2005 was the largest party short of half the votes (lowest 46.4% in 1997). The effective number of parties has never reached even 2.7 by votes or 2.5 by seats. Will this result be significantly more fragmented? It seems likely.
The National Assembly is elected in a modestly proportional system: at least as of 2009, it was a 128 seats in districts with an average magnitude of just over seven, using simple quota and largest remainders. Since 2005, lists have been open.
The president is elected in a single round, by plurality.
(Past results referenced from data in my files)