The Illustris simulation framework has been used by a wide range of spin-off projects that focus on specific scientific questions. IllustrisTNG: The IllustrisTNG project, "the next generation" follow up to the original Illustris simulation, was first presented in July, 2017. A team of scientists from Germany and the U.S. led by Prof. Volker Springel. First, a new physical model was developed, which among other features included Magnetohydrodynamics planned three simulations, which used different volumes at different resolutions. The intermediate simulation (TNG100) was equivalent to the original Illustris simulation. Unlike Illustris, it was run on the Hazel Hen machine at the High Performance Computing Center, Stuttgart in Germany. Up to 25,000 computer cores were employed. In December 2018 the simulation data from IllustrisTNG was released publicly. The data service includes a JupyterLab interface. Auriga: The Auriga project consists of high-resolution zoom simulations of Milky Way-like dark matter halos to understand the formation of our Milky Way galaxy. Thesan: The Thesan project is a radiative-transfer version of IllustrisTNG to explore the epoch of reionization. MillenniumTNG: The MillenniumTNG employs the IllustrisTNG galaxy formation model in a larger cosmological volume to explore the massive end of the halo mass function for detailed cosmological probe forecasts. TNG-Cluster: A suite of high-resolution zoom-in simulations of galaxy clusters.