Well I was looking for some operating systems for 8052 which can do the multitasking
To do multitasking (rather multiprocessing) on a '51 gang a bunch of them and let then each run a task and then let them taks on e.g. IIC. Running multiple tasks on a '51 is asking a pony to carry the worlds heaviest person.

Yes, multitasking OSs are available for the '51 e.g. CMX and the whole purpose of using a microcontroller as opposed to a microprocessor is lost.

The fact that a number of individuals want to do the wrong thing does, of course, make a business opportunity for someone to provide the tools.

The '51 is exceptionally good for what it is intended for, trying to make it do something else is bad design.

Erik