Magnite Inc. (formerly Rubicon Project) is an American online advertising technology firm based in Los Angeles, California.

Rubicon Project was founded in 2007 by Frank Addante, Craig Roah, Duc Chau and Julie Mattern, who had previously worked together at L90/adMonitor, an online advertising network.

[11] While the two businesses initially fell under Rubicon Project and operated as two separate brands,[11] the company rebranded under the name Magnite in June 2020.

[11] In February 2021, Magnite acquired SpotX from European entertainment network RTL Group for $1.17 billion in cash and stock.

[13] In September 2009, the Rubicon Project acquired OthersOnline, an audience profiling technology company based in Seattle.