MAYhem 1500 is a Doom II megawad for Boom-compatible ports, created by members of the Doomworld forums in May 2015. It is the fourth installment in the MAYhem series, an annual mapping event held throughout the month of May. The project was co-led by TheMionicDonut and Michael Fraize (Marcaek).
In this edition of MAYhem, mappers were restricted to a maximum of 1500 linedefs in their maps. In total, 34 maps were made during the month and an alpha was released on 16 June, followed by a number of betas starting from 3 July, however due to TheMionicDonut's absence, a final compilation was long delayed as the project was effectively without a leader. In January 2016, Marcaek took over as leader and pushed to get the WAD finalised before MAYhem 2016 was due to start. This target was not met, but with the help of Eric Baker (The Green Herring), a final release candidate was posted on 1 June, 2016. Following some further updates, it was uploaded to the /idgames archive on 10 June, though it was later followed by even more updates. The true final version, v1.50, was released on 23 September, 2016, almost fifteen months after the original event had finished.