The LEGO® MINDSTORMS® Robot Inventor kit (LEGO set number 51515) was released by LEGO in 2020, and LEGO has announced its retirement at the end of 2022. After this time, it may still be available new or used from various resellers, such as Amazon.
LEGO still offers a similar kit called Spike Prime, which uses the same hub, motor, and sensor electronics (in different colors), but the building parts inventory and programming software are both different, so the 51515 projects on this site will not be directly compatible.
The VEX® IQ Super Kit was sold by Innovation First under the VEX Robotics brand from 2012 to 2022. This kit is called the first generation of VEX IQ.
A second generation of VEX IQ was released in 2022 (but remains backordered as of December 2022), which updates the robot brain unit internals, other electronics, and contains an updated building parts inventory.
Projects on OneKitProjects use the VEXcode programming software.