Yet another serverless function as a service platform except this one runs your functions in WebWorker threads. Or alternatively you could self-host and use, for example, your own computer lab.
Read the wiki!
The project is open-source and designed to be easy to self-host. See the project GitHub.
Some recent web technologies really make this concept more desireable notably the following:
xss.software has completed a lot of tasks
Each worker is a computer connected to the network
Threads correspond to worker CPU cores
A load average of less than 1 means the system is underutilized
XSSaaS uses modern web technology in order to maximize performance and ease of use while avoiding the bloat of many popular frameworks.