Aviation gin is a "Dutch style" or genevere gin (a bit sweeter than one might normally expect compared to a traditional dry) and made from a base of 100% rye grain. They call it a "botanical democracy" of juniper, cardamon, coriander, lavender, anise, sarsaparilla, and orange zest.
In an interview with the Tasting Panel Magazine (January, 2013), founder Ryan Magarian mentions that the gin was invented as a result of his love of the classic Aviation cocktail, which he regarded as an awakening of his palate after the "un-approachability" of gin-and-tonic and gin-martini cocktails (heresy!). The gin came as a collaboration between distiller and bartender where Magarian worked with bartenders across the country for making the Aviation cocktail specifically with the balance of botanicals in this gin.
House Spirits was founded in 2004 by Lee Medoff and Christian Krogstad.