Super Mario Construct is an upcoming HTML5 Mario editor made by Luigibonus. It is intended to succeed Super Mario Flash 2 and friends, as Adobe Flash will be discontinued in 2020. The name Super Mario Construct was chosen because of the ability to create (construct) Mario levels, to immediately show that the game includes a Level Editor, and that the game is being developed in what is currently the most powerful HTML5 game engine, Construct.
The game is still in development, but there is a playable demo that can be played at this link.
It includes a various amount of Mario moves, including the all-new Spinjump.
There is also a fully functional level editor which already supports generating and loading level codes, so levels being made in the current demo can indeed be saved and shared with other people.