It's a red-letter day for supporters of instant runoff voting; after a three-cycle drought, the instant runoff system used for the Australian House of Representatives has elected a member of a third party. As there are 150 seats elected in the house each cycle, this means that one sixth of one percent of all elections were won by a third party member over the last four cycles.
Previous elections had seen a number of independent candidates win seats, but all of these had won their seats primarily because of previous membership in one of the two major parties, before falling out to run on their own (think Joe Lieberman in the US Senate, for comparison.)
Although The Coalition is officially two separate parties--the Liberal party and the National party--the two have an agreement whereby they do not challenge each others incumbents, have been united (as government or opposition) in the legislature for 60 years, and have formally combined as a single party in some Australian states. Virtually all Australian news sources refer to "the two party vote" as being between Labor and the Lib/Nat coalition.
Meanwhile, the Australian Senate uses single transferable vote, which is a system of proportional representation, on which IRV was based (but in such a way that it loses all proportionality.) There, the greens hold 5 of the 76 seats, while the Country Liberal and Family First parties hold 1 each (and 1 independent); for about 9% third-party representation, versus the 0.16% now available in the House.