Short answers, pulled from the story.
The IDW Publishing series redefined the origin story by revealing that Hamato Yoshi and his family were reincarnated from feudal Japan and transformed by alien mutagen in a New York City laboratory owned by Baxter Stockman. This tragic backstory replaced the traditional sewer origin and established Splinter as Yoshi and the Turtles as his sons.
Kevin Eastman, Tom Waltz, and Dan Duncan created the IDW Teenage Mutant Ninja Turtles series, which began in April 2011 and released its first issue on the 24th of August 2011. The series became the longest-running comic in the franchise's history, surpassing the 27-year run of Archie Comics' Teenage Mutant Ninja Turtles Adventures.
The City at War arc concluded with issue #100 in 2019 and featured a mutagen bomb attack that made the public aware of mutants, leading to the creation of Mutant Town in Manhattan. The storyline included conflicts with the Mutanimals, the birth of Zom's daughter, and the Armageddon Game which resulted in the destruction of Mutant Town's borders and the banishment of the Pantheons.
The IDW Teenage Mutant Ninja Turtles series featured crossovers with Batman, Mighty Morphin Power Rangers, Usagi Yojimbo, Ghostbusters, Street Fighter, Stranger Things, Masters of the Universe, Naruto, and Godzilla. These crossovers ran from 2012 to 2025 and included limited series, one-shots, and ongoing collaborations that expanded the Turtles' universe.
The Ronverse is a separate continuity focusing on a cyberpunk dystopia that features The Last Ronin, a story about a lone Michaelangelo seeking vengeance in a future New York City. The Ronverse includes The Last Ronin: Lost Years, The Last Ronin: Lost Day Special, and The Last Ronin II: Re-Evolution, which explore themes of legacy and sacrifice.