WebAppOS is an infrastructure for developing and running web applications. It defines a set of APIs that provide a seamless access to computation and memory resources for both the server-side and client-side code. Thus, web applications can be developed like traditional desktop applications assuming single PC as a target.

WebAppOS is open-source software. WebAppOS is written in Java and can be launched on any Java-capable server. WebAppOS provides web-based RAM analog that is shared between the client and the server. WebAppOS defines the concept of web-processor - a CPU analog for executing server-side code. WebAppOS is able to mount cloud drives and to access web-processors running in the cloud.